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  <title>CSS Box Sizing Module Level 4</title>
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 <body class="h-entry">
  <div class="head">
   <p data-fill-with="logo"><a class="logo" href="https://www.w3.org/"> <img alt="W3C" height="48" src="https://www.w3.org/StyleSheets/TR/2016/logos/W3C" width="72"> </a> </p>
   <h1 class="p-name no-ref" id="title">CSS Box Sizing Module Level 4</h1>
   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Editor’s Draft, <time class="dt-updated" datetime="1970-01-01">1 January 1970</time></span></h2>
   <details>
    <summary>Specification Metadata</summary>
    <div data-fill-with="spec-metadata">
     <dl>
      <dt>This version:
      <dd><a class="u-url" href="https://drafts.csswg.org/css-sizing">https://drafts.csswg.org/css-sizing</a>
      <dt>Latest published version:
      <dd><a href="https://www.w3.org/TR/css-sizing/">https://www.w3.org/TR/css-sizing/</a>
      <dt>Previous Versions:
      <dd><a href="https://www.w3.org/TR/2012/WD-css3-sizing-20120927/" rel="prev">https://www.w3.org/TR/2012/WD-css3-sizing-20120927/</a>
      <dt class="editor">Editors:
      <dd class="editor p-author h-card vcard" data-editor-id="42199"><a class="p-name fn u-url url" href="http://xanthir.com/contact/">Tab Atkins</a> (<span class="p-org org">Google</span>)
      <dd class="editor p-author h-card vcard" data-editor-id="35400"><a class="p-name fn u-url url" href="http://fantasai.inkedblade.net/contact">Elika J. Etemad / fantasai</a> (<span class="p-org org">Invited Expert</span>)
      <dd class="editor p-author h-card vcard"><a class="p-name fn u-url url" href="http://jensimmons.com/">Jen Simmons</a> (<span class="p-org org">Mozilla</span>)
      <dt>Suggest an Edit for this Spec:
      <dd><a href="https://github.com/w3c/csswg-drafts/blob/master/css-sizing-4/Overview.bs">GitHub Editor</a>
      <dt>Issue Tracking:
      <dd><a href="https://github.com/w3c/csswg-drafts/labels/css-sizing-4">GitHub Issues</a>
     </dl>
    </div>
   </details>
   <div data-fill-with="warning">
    <details class="annoying-warning" open>
     <summary>Not Ready For Implementation</summary>
     <p> This spec is not yet ready for implementation.
		It exists in this repository to record the ideas and promote discussion. </p>
     <p> Before attempting to implement this spec,
		please contact the CSSWG at www-style@w3.org. </p>
    </details>
   </div>
   <p class="copyright" data-fill-with="copyright"><a href="https://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 1970 <a href="https://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a href="https://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>, <a href="https://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>, <a href="https://www.keio.ac.jp/">Keio</a>, <a href="https://ev.buaa.edu.cn/">Beihang</a>). W3C <a href="https://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="https://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document">permissive document license</a> rules apply. </p>
   <hr title="Separator for header">
  </div>
  <div class="p-summary" data-fill-with="abstract">
   <h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
   <p>This is a delta spec over CSS Sizing Level 3.</p>
    <a href="https://www.w3.org/TR/CSS/">CSS</a> is a language for describing the rendering of structured documents
(such as HTML and XML)
on screen, on paper, etc. 
  </div>
  <h2 class="no-num no-toc no-ref heading settled" id="status"><span class="content">Status of this document</span></h2>
  <div data-fill-with="status">
   <p> This is a public copy of the editors’ draft.
	It is provided for discussion only and may change at any moment.
	Its publication here does not imply endorsement of its contents by W3C.
	Don’t cite this document other than as work in progress. </p>
   <p> <a href="https://github.com/w3c/csswg-drafts/issues">GitHub Issues</a> are preferred for discussion of this specification.
	When filing an issue, please put the text “css-sizing” in the title,
	preferably like this:
	“[css-sizing] <i data-lt>…summary of comment…</i>”.
	All issues and comments are <a href="https://lists.w3.org/Archives/Public/public-css-archive/">archived</a>,
	and there is also a <a href="https://lists.w3.org/Archives/Public/www-style/">historical archive</a>. </p>
   <p> This document was produced by the <a href="https://www.w3.org/Style/CSS/">CSS Working Group</a>. </p>
   <p> This document was produced by a group operating under
	the <a href="https://www.w3.org/Consortium/Patent-Policy/">W3C Patent Policy</a>.
	W3C maintains a <a href="https://www.w3.org/2004/01/pp-impl/32061/status" rel="disclosure">public list of any patent disclosures</a> made in connection with the deliverables of the group;
	that page also includes instructions for disclosing a patent.
	An individual who has actual knowledge of a patent which the individual believes contains <a href="https://www.w3.org/Consortium/Patent-Policy/#def-essential">Essential Claim(s)</a> must disclose the information in accordance with <a href="https://www.w3.org/Consortium/Patent-Policy/#sec-Disclosure">section 6 of the W3C Patent Policy</a>. </p>
   <p> This document is governed by the <a href="https://www.w3.org/2019/Process-20190301/" id="w3c_process_revision">1 March 2019 W3C Process Document</a>. </p>
   <p></p>
  </div>
  <div data-fill-with="at-risk"></div>
  <nav data-fill-with="table-of-contents" id="toc">
   <h2 class="no-num no-toc no-ref" id="contents">Table of Contents</h2>
   <ol class="toc" role="directory">
    <li>
     <a href="#intro"><span class="secno">1</span> <span class="content"> Introduction</span></a>
     <ol class="toc">
      <li><a href="#placement"><span class="secno">1.1</span> <span class="content"> Module interactions</span></a>
      <li><a href="#values"><span class="secno">1.2</span> <span class="content"> Values</span></a>
     </ol>
    <li>
     <a href="#terms"><span class="secno">2</span> <span class="content"> Terminology</span></a>
     <ol class="toc">
      <li><a href="#auto-box-sizes"><span class="secno">2.1</span> <span class="content"> Auto Box Sizes</span></a>
      <li><a href="#contributions"><span class="secno">2.2</span> <span class="content"> Intrinsic Size Contributions</span></a>
      <li><a href="#constraints"><span class="secno">2.3</span> <span class="content"> Intrinsic Size Constraints</span></a>
     </ol>
    <li>
     <a href="#specifying-sizes"><span class="secno">3</span> <span class="content"> Specifying Box Sizes</span></a>
     <ol class="toc">
      <li>
       <a href="#sizing-properties"><span class="secno">3.1</span> <span class="content"> Sizing Properties</span></a>
       <ol class="toc">
        <li><a href="#preferred-size-properties"><span class="secno">3.1.1</span> <span class="content"> Preferred Size Properties: the <span class="property">width</span> and <span class="property">height</span> properties</span></a>
        <li><a href="#min-size-properties"><span class="secno">3.1.2</span> <span class="content"> Minimum Size Properties: the <span class="property">min-width</span> and <span class="property">min-height</span> properties</span></a>
        <li><a href="#max-size-properties"><span class="secno">3.1.3</span> <span class="content"> Maximum Size Properties: the <span class="property">max-width</span> and <span class="property">max-height</span> properties</span></a>
       </ol>
      <li>
       <a href="#sizing-values"><span class="secno">3.2</span> <span class="content"> Sizing Values: the <span class="production">&lt;length-percentage></span>, <span class="css">auto</span> | <span class="css">none</span>, <span class="css">min-content</span>, <span class="css">max-content</span>, and <span class="css">fit-content()</span> values</span></a>
       <ol class="toc">
        <li><a href="#behave-auto"><span class="secno">3.2.1</span> <span class="content"> “Behaving as <span class="css">auto</span>”</span></a>
        <li><a href="#the-contain-floats-value"><span class="secno">3.2.2</span> <span class="content"> Containing or Excluding Floats</span></a>
       </ol>
      <li><a href="#box-sizing"><span class="secno">3.3</span> <span class="content"> Box Edges for Sizing: the <span class="property">box-sizing</span> property</span></a>
      <li><a href="#column-sizing"><span class="secno">3.4</span> <span class="content"> New Column Sizing Values: the <span class="css">min-content</span>, <span class="css">max-content</span>, and <span class="css">fit-content()</span> values</span></a>
     </ol>
    <li>
     <a href="#ratios"><span class="secno">4</span> <span class="content"> Aspect Ratios</span></a>
     <ol class="toc">
      <li>
       <a href="#aspect-ratio"><span class="secno">4.1</span> <span class="content"> Intrinsic Aspect Ratios: the <span class="property">aspect-ratio</span> property</span></a>
       <ol class="toc">
        <li><a href="#aspect-ratio-minimum"><span class="secno">4.1.1</span> <span class="content"> Automatic Content-based Minimum Sizes</span></a>
       </ol>
     </ol>
    <li>
     <a href="#intrinsic"><span class="secno">5</span> <span class="content"> Intrinsic Size Determination</span></a>
     <ol class="toc">
      <li><a href="#replaced-intrinsic"><span class="secno">5.1</span> <span class="content"> Intrinsic Sizes of Replaced Elements</span></a>
      <li><a href="#inline-intrinsic"><span class="secno">5.2</span> <span class="content"> Intrinsic Sizes of Non-Replaced Inlines</span></a>
      <li><a href="#block-intrinsic"><span class="secno">5.3</span> <span class="content"> Intrinsic Sizes of Non-Replaced Blocks</span></a>
      <li><a href="#table-intrinsic"><span class="secno">5.4</span> <span class="content"> Intrinsic Sizes in Table Layout</span></a>
      <li>
       <a href="#multicol-intrinsic"><span class="secno">5.5</span> <span class="content"> Intrinsic Sizes in Multi-column Layout</span></a>
       <ol class="toc">
        <li><a href="#multicol-min-content"><span class="secno">5.5.1</span> <span class="content"> Min-content Sizes in Multi-column Layout</span></a>
        <li><a href="#multicol-max-content"><span class="secno">5.5.2</span> <span class="content"> Max-content Sizes in Unconstrained-height Multi-column Layout</span></a>
        <li><a href="#multicol-max-content-restrained"><span class="secno">5.5.3</span> <span class="content"> Max-content Sizes in Constrained-height Multi-column Layout</span></a>
       </ol>
      <li><a href="#intrinsic-size-override"><span class="secno">5.6</span> <span class="content"> Overriding Intrinsic Sizes: the <span class="property">intrinsic-*</span> properties</span></a>
     </ol>
    <li><a href="#intrinsic-contribution"><span class="secno">6</span> <span class="content"> Intrinsic Size Contributions</span></a>
    <li>
     <a href="#extrinsic"><span class="secno">7</span> <span class="content"> Extrinsic Size Determination</span></a>
     <ol class="toc">
      <li><a href="#stretch-fit-sizing"><span class="secno">7.1</span> <span class="content"> Stretch-fit Sizing</span></a>
      <li><a href="#contain-fit-sizing"><span class="secno">7.2</span> <span class="content"> Contain-fit Sizing: stretching while maintaining an aspect ratio</span></a>
      <li><a href="#percentage-sizing"><span class="secno">7.3</span> <span class="content"> Percentage Sizing</span></a>
     </ol>
    <li><a href="#changes"><span class="secno"></span> <span class="content"> Changes</span></a>
    <li><a href="#acknowledgments"><span class="secno"></span> <span class="content"> Acknowledgments</span></a>
    <li><a href="#priv-sec"><span class="secno"></span> <span class="content"> Privacy and Security Considerations</span></a>
    <li>
     <a href="#conformance"><span class="secno"></span> <span class="content"> Conformance</span></a>
     <ol class="toc">
      <li><a href="#document-conventions"><span class="secno"></span> <span class="content"> Document conventions</span></a>
      <li><a href="#conform-classes"><span class="secno"></span> <span class="content"> Conformance classes</span></a>
      <li>
       <a href="#conform-responsible"><span class="secno"></span> <span class="content"> Requirements for Responsible Implementation of CSS</span></a>
       <ol class="toc">
        <li><a href="#conform-partial"><span class="secno"></span> <span class="content"> Partial Implementations</span></a>
        <li><a href="#conform-future-proofing"><span class="secno"></span> <span class="content"> Implementations of Unstable and Proprietary Features</span></a>
        <li><a href="#conform-testing"><span class="secno"></span> <span class="content"> Implementations of CR-level Features</span></a>
       </ol>
     </ol>
    <li>
     <a href="#index"><span class="secno"></span> <span class="content">Index</span></a>
     <ol class="toc">
      <li><a href="#index-defined-here"><span class="secno"></span> <span class="content">Terms defined by this specification</span></a>
      <li><a href="#index-defined-elsewhere"><span class="secno"></span> <span class="content">Terms defined by reference</span></a>
     </ol>
    <li>
     <a href="#references"><span class="secno"></span> <span class="content">References</span></a>
     <ol class="toc">
      <li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a>
      <li><a href="#informative"><span class="secno"></span> <span class="content">Informative References</span></a>
     </ol>
    <li><a href="#property-index"><span class="secno"></span> <span class="content">Property Index</span></a>
    <li><a href="#issues-index"><span class="secno"></span> <span class="content">Issues Index</span></a>
   </ol>
  </nav>
  <main>
   <h2 class="heading settled" data-level="1" id="intro"><span class="secno">1. </span><span class="content"> Introduction</span><a class="self-link" href="#intro"></a></h2>
   <p class="issue" id="issue-fb4505c3"><a class="self-link" href="#issue-fb4505c3"></a> This is a diff spec from <a href="https://www.w3.org/TR/css-sizing-3/">CSS Sizing Level 3</a>.
	It is currently an Exploratory Working Draft:
	if you are implementing anything, please use Level 3 as a reference.
	We will merge the Level 3 text into this draft once it reaches CR.</p>
   <h3 class="heading settled" data-level="1.1" id="placement"><span class="secno">1.1. </span><span class="content"> Module interactions</span><a class="self-link" href="#placement"></a></h3>
   <p>This module extends the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-width" id="ref-for-propdef-width">width</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-height" id="ref-for-propdef-height">height</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-width" id="ref-for-propdef-min-width">min-width</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-height" id="ref-for-propdef-min-height">min-height</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-max-width" id="ref-for-propdef-max-width">max-width</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-max-height" id="ref-for-propdef-max-height">max-height</a>, and <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-width" id="ref-for-propdef-column-width">column-width</a> features defined in <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a> chapter 10 and in <a data-link-type="biblio" href="#biblio-css3col">[CSS3COL]</a> </p>
   <h3 class="heading settled" data-level="1.2" id="values"><span class="secno">1.2. </span><span class="content"> Values</span><a class="self-link" href="#values"></a></h3>
   <p>This specification follows the <a href="https://www.w3.org/TR/CSS2/about.html#property-defs">CSS property definition conventions</a> from <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a>.
	Value types not defined in this specification are defined in CSS Values &amp; Units <a data-link-type="biblio" href="#biblio-css-values-3">[CSS-VALUES-3]</a>.
	Other CSS modules may expand the definitions of these value types.</p>
   <p>In addition to the property-specific values listed in their definitions,
	all properties defined in this specification
	also accept the <a data-link-type="dfn" href="https://drafts.csswg.org/css-values-4/#css-wide-keywords" id="ref-for-css-wide-keywords">CSS-wide keywords</a> keywords as their property value.
	For readability they have not been repeated explicitly.</p>
   <h2 class="heading settled" data-level="2" id="terms"><span class="secno">2. </span><span class="content"> Terminology</span><a class="self-link" href="#terms"></a></h2>
   <h3 class="heading settled" data-level="2.1" id="auto-box-sizes"><span class="secno">2.1. </span><span class="content"> Auto Box Sizes</span><a class="self-link" href="#auto-box-sizes"></a></h3>
   <h3 class="heading settled" data-level="2.2" id="contributions"><span class="secno">2.2. </span><span class="content"> Intrinsic Size Contributions</span><a class="self-link" href="#contributions"></a></h3>
   <h3 class="heading settled" data-dfn-type="dfn" data-export data-level="2.3" data-lt="intrinsic size constraint" id="constraints"><span class="secno">2.3. </span><span class="content"> Intrinsic Size Constraints</span><a class="self-link" href="#constraints"></a></h3>
   <h2 class="heading settled" data-level="3" id="specifying-sizes"><span class="secno">3. </span><span class="content"> Specifying Box Sizes</span><span id="size-keywords"></span><a class="self-link" href="#specifying-sizes"></a></h2>
   <h3 class="heading settled" data-level="3.1" id="sizing-properties"><span class="secno">3.1. </span><span class="content"> Sizing Properties</span><a class="self-link" href="#sizing-properties"></a></h3>
   <h4 class="heading settled" data-dfn-type="dfn" data-export data-level="3.1.1" data-lt="preferred size property" id="preferred-size-properties"><span class="secno">3.1.1. </span><span class="content"> Preferred Size Properties: the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-width" id="ref-for-propdef-width①">width</a> and <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-height" id="ref-for-propdef-height①">height</a> properties</span><a class="self-link" href="#preferred-size-properties"></a></h4>
   <h4 class="heading settled" data-dfn-type="dfn" data-export data-level="3.1.2" data-lt="min size property" id="min-size-properties"><span class="secno">3.1.2. </span><span class="content"> Minimum Size Properties: the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-width" id="ref-for-propdef-min-width①">min-width</a> and <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-height" id="ref-for-propdef-min-height①">min-height</a> properties</span><a class="self-link" href="#min-size-properties"></a></h4>
   <h4 class="heading settled" data-dfn-type="dfn" data-export data-level="3.1.3" data-lt="max size property" id="max-size-properties"><span class="secno">3.1.3. </span><span class="content"> Maximum Size Properties: the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-max-width" id="ref-for-propdef-max-width①">max-width</a> and <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-max-height" id="ref-for-propdef-max-height①">max-height</a> properties</span><a class="self-link" href="#max-size-properties"></a></h4>
   <h3 class="heading settled" data-level="3.2" id="sizing-values"><span class="secno">3.2. </span><span class="content"> Sizing Values: the <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage" id="ref-for-typedef-length-percentage">&lt;length-percentage></a>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto">auto</a> | <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-max-width-none" id="ref-for-valdef-max-width-none">none</a>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-min-content" id="ref-for-valdef-width-min-content">min-content</a>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-max-content" id="ref-for-valdef-width-max-content">max-content</a>, and <span class="css">fit-content()</span> values</span><span id="width-height-keywords"></span><a class="self-link" href="#sizing-values"></a></h3>
   <h4 class="heading settled" data-level="3.2.1" id="behave-auto"><span class="secno">3.2.1. </span><span class="content"> “Behaving as <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto①">auto</a>”</span><a class="self-link" href="#behave-auto"></a></h4>
   <h4 class="heading settled" data-level="3.2.2" id="the-contain-floats-value"><span class="secno">3.2.2. </span><span class="content"> Containing or Excluding Floats</span><a class="self-link" href="#the-contain-floats-value"></a></h4>
   <h3 class="heading settled caniuse-paneled" data-level="3.3" id="box-sizing"><span class="secno">3.3. </span><span class="content"> Box Edges for Sizing: the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-sizing-3/#propdef-box-sizing" id="ref-for-propdef-box-sizing">box-sizing</a> property</span><a class="self-link" href="#box-sizing"></a></h3>
   <h3 class="heading settled" data-level="3.4" id="column-sizing"><span class="secno">3.4. </span><span class="content"> New Column Sizing Values: the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-column-width-min-content" id="ref-for-valdef-column-width-min-content">min-content</a>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-column-width-max-content" id="ref-for-valdef-column-width-max-content">max-content</a>, and <span class="css">fit-content()</span> values</span><a class="self-link" href="#column-sizing"></a></h3>
   <h2 class="heading settled" data-level="4" id="ratios"><span class="secno">4. </span><span class="content"> Aspect Ratios</span><a class="self-link" href="#ratios"></a></h2>
   <p class="issue" id="issue-bf01a94d"><a class="self-link" href="#issue-bf01a94d"></a> This section is a rough draft proposal.
See discussion in <a href="https://github.com/w3c/csswg-drafts/issues/333">Issue 333</a> and <a href="https://github.com/w3c/csswg-drafts/issues/1173">Issue 1173</a>.</p>
   <h3 class="heading settled" data-level="4.1" id="aspect-ratio"><span class="secno">4.1. </span><span class="content"> Intrinsic Aspect Ratios: the <a class="property" data-link-type="propdesc" href="#propdef-aspect-ratio" id="ref-for-propdef-aspect-ratio">aspect-ratio</a> property</span><a class="self-link" href="#aspect-ratio"></a></h3>
   <table class="def propdef" data-link-for-hint="aspect-ratio">
    <tbody>
     <tr>
      <th>Name:
      <td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-aspect-ratio">aspect-ratio</dfn>
     <tr class="value">
      <th><a href="https://drafts.csswg.org/css-values/#value-defs">Value:</a>
      <td class="prod">auto <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one">|</a> <a class="production css" data-link-type="type" href="https://drafts.csswg.org/mediaqueries-4/#typedef-ratio" id="ref-for-typedef-ratio">&lt;ratio></a> 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#initial-values">Initial:</a>
      <td>auto 
     <tr>
      <th>Applies to:
      <td>all elements except <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#inline-box" id="ref-for-inline-box">inline boxes</a> and internal ruby or table boxes 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#inherited-property">Inherited:</a>
      <td>no 
     <tr>
      <th><a href="https://drafts.csswg.org/css-values/#percentages">Percentages:</a>
      <td>n/a 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#computed">Computed value:</a>
      <td>specified keyword or a pair of numbers 
     <tr>
      <th>Canonical order:
      <td>per grammar 
     <tr>
      <th><a href="https://drafts.csswg.org/web-animations/#animation-type">Animation type:</a>
      <td>discrete 
   </table>
   <p>This property sets a <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="preferred-aspect-ratio">preferred aspect ratio</dfn> for the box,
	which will be used in the calculation of <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto②">auto</a> sizes
	and some other layout functions.
	The box’s <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#automatic-size" id="ref-for-automatic-size">automatic sizes</a> are then calculated the same as for
	a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#replaced-element" id="ref-for-replaced-element">replaced element</a> with an <a data-link-type="dfn" href="https://drafts.csswg.org/css-images-3/#intrinsic-aspect-ratio" id="ref-for-intrinsic-aspect-ratio">intrinsic aspect ratio</a>,
	see e.g. <a href="https://www.w3.org/TR/CSS2/visudet.html">CSS2 § 10</a> and <a href="https://www.w3.org/TR/css-flexbox-1/#algo-main-item">CSS Flexible Box Model Level 1 § 9.2</a>.
	The axis in which the <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#preferred-size" id="ref-for-preferred-size">preferred size</a> calculation
	depends on this aspect ratio
	is called the <dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="ratio-dependent-axis">ratio-dependent axis</dfn>,
	and the resulting size is <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#definite" id="ref-for-definite">definite</a> if its input sizes are also <span id="ref-for-definite①">definite</span>.</p>
   <dl>
    <dt><dfn class="css" data-dfn-for="aspect-ratio" data-dfn-type="value" data-export id="valdef-aspect-ratio-auto">auto<a class="self-link" href="#valdef-aspect-ratio-auto"></a></dfn> 
    <dd> <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#replaced-element" id="ref-for-replaced-element①">Replaced elements</a> with an <a data-link-type="dfn" href="https://drafts.csswg.org/css-images-3/#intrinsic-aspect-ratio" id="ref-for-intrinsic-aspect-ratio①">intrinsic aspect ratio</a> use that aspect ratio;
			otherwise the box has no <a data-link-type="dfn" href="#preferred-aspect-ratio" id="ref-for-preferred-aspect-ratio">preferred aspect ratio</a>.
			Size calculations involving <span id="ref-for-intrinsic-aspect-ratio②">intrinsic aspect ratio</span> work with the <a data-link-type="dfn" href="https://drafts.csswg.org/css-box-3/#content-box" id="ref-for-content-box">content box</a> dimensions always. 
    <dt><dfn class="css" data-dfn-for="aspect-ratio" data-dfn-type="value" data-export id="valdef-aspect-ratio-ratio"><a class="production css" data-link-type="type" href="https://drafts.csswg.org/mediaqueries-4/#typedef-ratio" id="ref-for-typedef-ratio①">&lt;ratio></a><a class="self-link" href="#valdef-aspect-ratio-ratio"></a></dfn> 
    <dd> The box’s <a data-link-type="dfn" href="#preferred-aspect-ratio" id="ref-for-preferred-aspect-ratio①">preferred aspect ratio</a> is the specified ratio
			of <span class="css">width / height</span>.
			Size calculations involving <span id="ref-for-preferred-aspect-ratio②">preferred aspect ratio</span> work with the dimensions of the box specified by <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-sizing-3/#propdef-box-sizing" id="ref-for-propdef-box-sizing①">box-sizing</a>. 
   </dl>
   <p class="note" role="note"><span>Note:</span> If a box has both a <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-width" id="ref-for-propdef-width②">width</a> and a <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-height" id="ref-for-propdef-height②">height</a> that are not <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#automatic-size" id="ref-for-automatic-size①">automatic</a> (or, in the case of a <a data-link-type="dfn" href="https://drafts.csswg.org/css-flexbox-1/#flex-item" id="ref-for-flex-item">flex item</a>,
	both a <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-flexbox-1/#valdef-flex-basis-content" id="ref-for-valdef-flex-basis-content">content</a> flex basis and
	a non-<span id="ref-for-automatic-size②">automatic</span> preferred <a data-link-type="dfn" href="https://drafts.csswg.org/css-flexbox-1/#cross-size" id="ref-for-cross-size">cross size</a>),
	then the <a data-link-type="dfn" href="#preferred-aspect-ratio" id="ref-for-preferred-aspect-ratio③">preferred aspect ratio</a> has no effect:
	at least one of these sizes must be <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto③">auto</a> (/<span class="css" id="ref-for-valdef-flex-basis-content①">content</span>)
	for the <span id="ref-for-preferred-aspect-ratio④">preferred aspect ratio</span> to have an impact on sizing.</p>
   <div class="example" id="example-95a95149">
    <a class="self-link" href="#example-95a95149"></a> This example sets each item in the grid to render as a square,
		determining the number of items and their widths by the available space. 
<pre class="highlight"><c- p>&lt;</c-><c- f>ul</c-><c- p>></c->
  <c- p>&lt;</c-><c- f>li</c-><c- p>></c->…
  <c- p>&lt;</c-><c- f>li</c-><c- p>></c->…
  <c- p>&lt;</c-><c- f>li</c-><c- p>></c->…
  <c- p>&lt;</c-><c- f>li</c-><c- p>></c->…
<c- p>&lt;/</c-><c- f>ul</c-><c- p>></c->
</pre>
<pre class="highlight"><c- f>ul </c-><c- p>{</c->
  <c- k>display</c-><c- p>:</c-> grid<c- p>;</c->
  <c- k>grid-template-columns</c-><c- p>:</c-> <c- nf>repeat</c-><c- p>(</c->auto-fill<c- p>,</c-> <c- nf>minmax</c-><c- p>(</c-><c- m>12</c-><c- l>em</c-><c- p>,</c-> <c- m>1</c-><c- l>fr</c-><c- p>));</c->
<c- p>}</c->
<c- f>li </c-><c- p>{</c->
  <c- k>aspect-ratio</c-><c- p>:</c-> <c- m>1</c-><c- p>/</c-><c- m>1</c-><c- p>;</c->
  <c- k>overflow</c-><c- p>:</c-> auto<c- p>;</c->
<c- p>}</c->
</pre>
   </div>
   <div class="example" id="example-2476aa5b">
    <a class="self-link" href="#example-2476aa5b"></a> This example uses the <code><a data-link-type="element" href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element" id="ref-for-the-iframe-element">iframe</a></code> element’s <code>width</code> and <code>height</code> attributes
		to set the <a class="property" data-link-type="propdesc" href="#propdef-aspect-ratio" id="ref-for-propdef-aspect-ratio①">aspect-ratio</a> property,
		giving the iframe an aspect ratio to use for sizing
		so that it behaves exactly like an image with that aspect ratio. 
<pre class="highlight"><c- p>&lt;</c-><c- f>iframe</c->
  <c- e>src</c-><c- o>=</c-><c- s>"https://www.youtube.com/embed/0Gr1XSyxZy0"</c->
  <c- e>width</c-><c- o>=</c-><c- s>560</c->
  <c- e>height</c-><c- o>=</c-><c- s>315</c-><c- p>></c->
</pre>
<pre class="highlight"><c- n>@supports</c-> <c- p>(</c->aspect-ratio<c- f>: attr(width) / 1) </c-><c- p>{</c->
  iframe {
    aspect-ratio: attr(width) / attr(height);
    width: 100%;
    height: auto;
  }
}
</pre>
    <p class="issue" id="issue-08ed422b"><a class="self-link" href="#issue-08ed422b"></a> Can we just slip this <a class="property" data-link-type="propdesc" href="#propdef-aspect-ratio" id="ref-for-propdef-aspect-ratio②">aspect-ratio</a> rule
		into the UA default style sheet for images,
		so that they have an aspect ratio while they load?
		This would avoid the need for extra reflows after loading.</p>
   </div>
   <p>On non-replaced elements with an <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto④">auto</a> <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#inline-size" id="ref-for-inline-size">inline size</a> (or any replaced element whose intrinsic <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#block-size" id="ref-for-block-size">block size</a> depends on its <span id="ref-for-inline-size①">inline size</span>),
	the intrinsic <span id="ref-for-block-size①">block sizes</span> of the box
	are assumed to be zero
	when applying <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-logical-1/#propdef-min-block-size" id="ref-for-propdef-min-block-size">min-block-size</a> to the aspect ratio calculations,
	and assumed to be infinity
	when applying <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-logical-1/#propdef-max-block-size" id="ref-for-propdef-max-block-size">max-block-size</a> to the aspect ratio calculations.
	These limits take effect as usual for non-replaced elements
	once the <span id="ref-for-inline-size②">inline size</span> is resolved.</p>
   <div class="example" id="example-713abd19">
    <a class="self-link" href="#example-713abd19"></a> For example, given a (<a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#horizontal-writing-mode" id="ref-for-horizontal-writing-mode">horizontal writing mode</a>) element with 
<pre>width: auto;
min-height: min-content;
aspect-ratio: 1/1;
</pre>
    <p>using the aspect ratio to resolve the width
		would require knowing the min-content height of the element.</p>
    <p>Since for a non-replaced element,
		this value is not known until the width is resolved,
		we assume the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-height" id="ref-for-propdef-min-height②">min-height</a> value is zero
		while resolving the width.</p>
    <p>Then, once the width is known, we resolve the height,
		taking into account the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-min-content" id="ref-for-valdef-width-min-content①">min-content</a> minimum.</p>
   </div>
   <h4 class="heading settled" data-level="4.1.1" id="aspect-ratio-minimum"><span class="secno">4.1.1. </span><span class="content"> Automatic Content-based Minimum Sizes</span><a class="self-link" href="#aspect-ratio-minimum"></a></h4>
   <p>In order to avoid unintentional overflow,
	the <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#automatic-minimum-size" id="ref-for-automatic-minimum-size">automatic minimum size</a> in the <a data-link-type="dfn" href="#ratio-dependent-axis" id="ref-for-ratio-dependent-axis">ratio-dependent axis</a> of a box with a <a data-link-type="dfn" href="#preferred-aspect-ratio" id="ref-for-preferred-aspect-ratio⑤">preferred aspect ratio</a> that is neither a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#replaced-element" id="ref-for-replaced-element②">replaced element</a> nor a <a data-link-type="dfn" href="https://drafts.csswg.org/css-overflow-3/#scroll-container" id="ref-for-scroll-container">scroll container</a> is the minimum of
	its <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content" id="ref-for-min-content">min-content size</a> and its <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-width" id="ref-for-max-width">maximum size</a>.</p>
   <div class="example" id="example-1ffd5cff">
    <a class="self-link" href="#example-1ffd5cff"></a> In the following example,
		the box is as wide as the container (as usual),
		and its height is as tall as needed to contain its content
		but at least as tall as it is wide. 
<pre>div {
  aspect-ratio: 1/1;
  /* 'width' and 'height' both default to 'auto' */
}
</pre>
<pre class="figure">+----------+  +----------+  +----------+
| ~~~~~~~~ |  | ~~~~~~~~ |  | ~~~~~~~~ |
| ~~~~~~~~ |  | ~~~~~~~~ |  | ~~~~~~~~ |
| ~~~~~~~  |  | ~~~~~~~~ |  | ~~~~~~~~ |
|          |  | ~~~      |  | ~~~~~~~~ |
+----------+  +----------+  | ~~~~~~~~ |
                            | ~~~~~~   |
                            +----------+
</pre>
    <p>When <a class="css" data-link-type="propdesc" href="https://drafts.csswg.org/css-overflow-3/#propdef-overflow" id="ref-for-propdef-overflow">overflow: auto</a> is specified, however,
		even the box with excess content maintains the 1:1 aspect ratio.</p>
<pre>div {
  overflow: auto;
  aspect-ratio: 1/1;
}
</pre>
<pre class="figure">+----------+  +----------+  +----------+
| ~~~~~~~~ |  | ~~~~~~~~ |  | ~~~~~~~~^|
| ~~~~~~~~ |  | ~~~~~~~~ |  | ~~~~~~~~ |
| ~~~~~~~  |  | ~~~~~~~~ |  | ~~~~~~~~ |
|          |  | ~~~      |  | ~~~~~~~~v|
+----------+  +----------+  +----------+
</pre>
    <p>Overriding the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-height" id="ref-for-propdef-min-height③">min-height</a> property also maintains the 1:1 aspect ratio,
		but will result in content overflowing the box
		if it is not otherwise handled.</p>
<pre>div {
  aspect-ratio: 1/1;
  min-height: 0;
}
</pre>
<pre class="figure">+----------+  +----------+  +----------+
| ~~~~~~~~ |  | ~~~~~~~~ |  | ~~~~~~~~ |
| ~~~~~~~~ |  | ~~~~~~~~ |  | ~~~~~~~~ |
| ~~~~~~~  |  | ~~~~~~~~ |  | ~~~~~~~~ |
|          |  | ~~~      |  | ~~~~~~~~ |
+----------+  +----------+  +-~~~~~~~~-+
                              ~~~~~~    
</pre>
   </div>
   <h2 class="heading settled" data-level="5" id="intrinsic"><span class="secno">5. </span><span class="content"> Intrinsic Size Determination</span><a class="self-link" href="#intrinsic"></a></h2>
   <p class="issue" id="issue-05e1e44b"><a class="self-link" href="#issue-05e1e44b"></a> <strong>Need to Sync This Section With Level 3 It is Super Out Of Date</strong></p>
   <p><dfn class="dfn-paneled" data-dfn-type="dfn" data-export data-lt="intrinsic size" id="intrinsic-size">Intrinsic sizing</dfn> determines sizes based on the contents of a box,
	without regard for the context in which it is placed.</p>
   <p>Precisely how to calculate the <a data-link-type="dfn" href="#intrinsic-size" id="ref-for-intrinsic-size">intrinsic size</a> of a box depends on its layout mode;
	the following subsections define intrinsic sizing for several types of layouts.
	Individual layout modes,
	such as Flexbox or Grid,
	can define their own intrinsic sizing rules.</p>
   <p>If a box has an <a data-link-type="dfn" href="#explicit-intrinsic-inner-size" id="ref-for-explicit-intrinsic-inner-size">explicit intrinsic inner size</a> in an axis,
	then that is all of its <a data-link-type="dfn" href="#intrinsic-size" id="ref-for-intrinsic-size①">intrinsic sizes</a> in that axis.
	If the other axis does not have an <span id="ref-for-explicit-intrinsic-inner-size①">explicit intrinsic inner size</span>,
	then its intrinsic sizes are determined normally,
	without regard for the <span id="ref-for-explicit-intrinsic-inner-size②">explicit intrinsic inner size</span> in the first axis.</p>
   <h3 class="heading settled" data-level="5.1" id="replaced-intrinsic"><span class="secno">5.1. </span><span class="content"> Intrinsic Sizes of Replaced Elements</span><a class="self-link" href="#replaced-intrinsic"></a></h3>
   <p> For replaced elements,
		the <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content" id="ref-for-min-content①">min-content size</a> and <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content" id="ref-for-max-content">max-content size</a> are equivalent
		and correspond to the appropriate dimension of the concrete object size returned by
		the <a href="https://www.w3.org/TR/css3-images/#default-sizing">default sizing algorithm</a> <a data-link-type="biblio" href="#biblio-css3-images">[CSS3-IMAGES]</a> of the element,
		calculated with an unconstrained specified size. </p>
   <p>The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution">min-content contribution</a> and <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution" id="ref-for-max-content-contribution">max-content contribution</a> in each axis
	is the element’s specified outer size in that axis, if definite;
	otherwise, they are the <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content" id="ref-for-min-content②">min-content size</a>, as specified above,
	plus the element’s margin/border/padding in that axis,
	clamped by the element’s min and max size properties in that axis.</p>
   <h3 class="heading settled" data-level="5.2" id="inline-intrinsic"><span class="secno">5.2. </span><span class="content"> Intrinsic Sizes of Non-Replaced Inlines</span><a class="self-link" href="#inline-intrinsic"></a></h3>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-inline-size" id="ref-for-min-content-inline-size">min-content inline size</a> of an inline box
		is the length of the largest unbreakable sequence of inline content.
		The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution①">min-content inline-size contribution</a> of an inline box
		is its <span id="ref-for-min-content-inline-size①">min-content inline size</span>,
		plus any <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#inline-axis" id="ref-for-inline-axis">inline-axis</a> margin, border, and padding
		adjacent to that sequence. </p>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size" id="ref-for-max-content-inline-size">max-content inline size</a> of an inline box
		is the length of the largest sequence of inline content
		on a single line
		when only forced line breaks are taken.
		The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution" id="ref-for-max-content-contribution①">max-content inline-size contribution</a> of an inline box
		is its <span id="ref-for-max-content-inline-size①">max-content inline size</span>,
		plus any <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#inline-axis" id="ref-for-inline-axis①">inline-axis</a> margin, border, and padding
		adjacent to that sequence. </p>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-block-size" id="ref-for-min-content-block-size">min-content block size</a>, <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-block-size" id="ref-for-max-content-block-size">max-content block size</a>, <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution②">min-content block-size contribution</a>, and <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution" id="ref-for-max-content-contribution②">max-content block-size contribution</a> of an inline box
		are the distance from the head edge of the first line box
		to the foot edge of the last line box
		on which the inline appears. </p>
   <h3 class="heading settled" data-level="5.3" id="block-intrinsic"><span class="secno">5.3. </span><span class="content"> Intrinsic Sizes of Non-Replaced Blocks</span><a class="self-link" href="#block-intrinsic"></a></h3>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-inline-size" id="ref-for-min-content-inline-size②">min-content inline size</a> of a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#block-container" id="ref-for-block-container">block container box</a> is the largest <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution③">min-content inline-size contribution</a> of its in-flow or floated children. </p>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size" id="ref-for-max-content-inline-size②">max-content inline size</a> of a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#block-container" id="ref-for-block-container①">block container box</a> is the inline-size of the box after layout,
		if all children are sized under a <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-constraint" id="ref-for-max-content-constraint">max-content constraint</a>. </p>
   <p> If the computed inline-size of a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#block-level-box" id="ref-for-block-level-box">block-level box</a> is <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-min-content" id="ref-for-valdef-width-min-content②">min-content</a>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-max-content" id="ref-for-valdef-width-max-content①">max-content</a>, or a <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#definite" id="ref-for-definite②">definite size</a>,
		its <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution④">min-content inline-size contribution</a> is that size
		plus any <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#inline-axis" id="ref-for-inline-axis②">inline-axis</a> margin, border, and padding.
		Otherwise, if the computed inline-size of the block is <span class="css">fit-content</span>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto⑤">auto</a>, or <span class="css">stretch</span>,
		its <span id="ref-for-min-content-contribution⑤">min-content inline-size contribution</span> is its <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-inline-size" id="ref-for-min-content-inline-size③">min-content inline size</a> plus any <span id="ref-for-inline-axis③">inline-axis</span> margin, border, and padding. </p>
   <p> If the computed inline-size of a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#block-level-box" id="ref-for-block-level-box①">block-level box</a> is <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-min-content" id="ref-for-valdef-width-min-content③">min-content</a>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-max-content" id="ref-for-valdef-width-max-content②">max-content</a>, or a <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#definite" id="ref-for-definite③">definite size</a>,
		its <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution" id="ref-for-max-content-contribution③">max-content inline-size contribution</a> is that size
		plus any <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#inline-axis" id="ref-for-inline-axis④">inline-axis</a> margin, border, and padding.
		Otherwise, if the computed inline-size of the block is <span class="css">fit-content</span>, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto⑥">auto</a>, or <span class="css">stretch</span>,
		its <span id="ref-for-max-content-contribution④">max-content inline-size contribution</span> is its <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size" id="ref-for-max-content-inline-size③">max-content inline size</a> plus any <span id="ref-for-inline-axis⑤">inline-axis</span> margin, border, and padding. </p>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-block-size" id="ref-for-min-content-block-size①">min-content block size</a> and <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-block-size" id="ref-for-max-content-block-size①">max-content block size</a> of a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#block-container" id="ref-for-block-container②">block container box</a> is the content block-size as defined
		(for horizontal writing modes)
		in <a href="https://www.w3.org/TR/CSS2/visudet.html#normal-block">CSS2.1§10.6.3</a> and <a href="https://www.w3.org/TR/CSS2/tables.html#height-layout">CSS2.1§17.5.3</a> for elements with <a class="css" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-height" id="ref-for-propdef-height③">height: auto</a>,
		and analogously for vertical writing modes. </p>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution⑥">min-content block-size contribution</a> and <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution" id="ref-for-max-content-contribution⑤">max-content block-size contribution</a> of a <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#block-level-box" id="ref-for-block-level-box②">block-level box</a> is the block-size of the block after layout,
		plus any <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#block-axis" id="ref-for-block-axis">block-axis</a> margin, border, and padding. </p>
   <p class="issue" id="issue-ac962596"><a class="self-link" href="#issue-ac962596"></a> Need to handle floats.
	See <a href="https://lists.w3.org/Archives/Public/www-style/2014Oct/0061.html">Greg’s issue</a> and <a href="https://lists.w3.org/Archives/Public/www-style/2014Nov/0085.html">dbaron’s response</a>.</p>
   <h3 class="heading settled" data-level="5.4" id="table-intrinsic"><span class="secno">5.4. </span><span class="content"> Intrinsic Sizes in Table Layout</span><a class="self-link" href="#table-intrinsic"></a></h3>
   <p class="issue" id="issue-fbee5e7e"><a class="self-link" href="#issue-fbee5e7e"></a> ¯\_(ツ)_/¯ </p>
   <h3 class="heading settled" data-level="5.5" id="multicol-intrinsic"><span class="secno">5.5. </span><span class="content"> Intrinsic Sizes in Multi-column Layout</span><a class="self-link" href="#multicol-intrinsic"></a></h3>
   <h4 class="heading settled" data-level="5.5.1" id="multicol-min-content"><span class="secno">5.5.1. </span><span class="content"> Min-content Sizes in Multi-column Layout</span><a class="self-link" href="#multicol-min-content"></a></h4>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-inline-size" id="ref-for-min-content-inline-size④">min-content inline size</a> of a multi-column container
		with a computed <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-width" id="ref-for-propdef-column-width①">column-width</a> not <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-multicol-1/#valdef-column-width-auto" id="ref-for-valdef-column-width-auto">auto</a> is the smaller of
		its <span class="property" id="ref-for-propdef-column-width②">column-width</span> and the largest <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution⑦">min-content inline-size contribution</a> of its contents. </p>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-inline-size" id="ref-for-min-content-inline-size⑤">min-content inline size</a> of a multi-column container
		with a computed <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-width" id="ref-for-propdef-column-width③">column-width</a> of <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-multicol-1/#valdef-column-width-auto" id="ref-for-valdef-column-width-auto①">auto</a> is the largest <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution⑧">min-content inline-size contribution</a> of its contents
		multiplied by its <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-count" id="ref-for-propdef-column-count">column-count</a> (treating <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-multicol-1/#valdef-column-count-auto" id="ref-for-valdef-column-count-auto">auto</a> as <span class="css">1</span>),
		plus its <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-align-3/#propdef-column-gap" id="ref-for-propdef-column-gap">column-gap</a> multiplied by <span class="property" id="ref-for-propdef-column-count①">column-count</span> minus 1. </p>
   <h4 class="heading settled" data-level="5.5.2" id="multicol-max-content"><span class="secno">5.5.2. </span><span class="content"> Max-content Sizes in Unconstrained-height Multi-column Layout</span><a class="self-link" href="#multicol-max-content"></a></h4>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size" id="ref-for-max-content-inline-size④">max-content inline size</a> of a multi-column container
		with unrestrained column heights
		and a computed <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-count" id="ref-for-propdef-column-count②">column-count</a> not <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-multicol-1/#valdef-column-count-auto" id="ref-for-valdef-column-count-auto①">auto</a> is its <span class="property" id="ref-for-propdef-column-count③">column-count</span> multiplied by the larger of
		its <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-width" id="ref-for-propdef-column-width④">column-width</a> (treating <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-multicol-1/#valdef-column-width-auto" id="ref-for-valdef-column-width-auto②">auto</a> as zero)
		and the largest <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution⑨">min-content inline-size contribution</a> of its contents,
		plus its <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-align-3/#propdef-column-gap" id="ref-for-propdef-column-gap①">column-gap</a> multiplied by <span class="property" id="ref-for-propdef-column-count④">column-count</span> minus 1. </p>
   <p class="note" role="note"> Note that the contents of the multi-column container
		can still grow to be wider and shorter
		if the resulting column width is still smaller
		than the largest <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution" id="ref-for-max-content-contribution⑥">max-content inline-size contribution</a> of its contents. </p>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size" id="ref-for-max-content-inline-size⑤">max-content inline size</a> of a multi-column container
		with unrestrained column heights
		and a computed <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-count" id="ref-for-propdef-column-count⑤">column-count</a> of <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-multicol-1/#valdef-column-count-auto" id="ref-for-valdef-column-count-auto②">auto</a> is its <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-multicol-1/#propdef-column-width" id="ref-for-propdef-column-width⑤">column-width</a> multiplied by the number of columns obtained by taking all allowed column breaks <a data-link-type="biblio" href="#biblio-css3-break">[CSS3-BREAK]</a>,
		plus its <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-align-3/#propdef-column-gap" id="ref-for-propdef-column-gap②">column-gap</a> multiplied by that same number of columns minus 1. </p>
   <h4 class="heading settled" data-level="5.5.3" id="multicol-max-content-restrained"><span class="secno">5.5.3. </span><span class="content"> Max-content Sizes in Constrained-height Multi-column Layout</span><a class="self-link" href="#multicol-max-content-restrained"></a></h4>
   <p> The <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size" id="ref-for-max-content-inline-size⑥">max-content inline size</a> of a multi-column container
		with restrained-height columns (i.e. a specified <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-height" id="ref-for-propdef-height④">height</a> or <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-max-height" id="ref-for-propdef-max-height②">max-height</a>, or whichever properties map to the <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#block-size" id="ref-for-block-size②">block size</a> of the element)
		is the <a data-link-type="dfn" href="https://drafts.csswg.org/css-writing-modes-4/#inline-size" id="ref-for-inline-size③">inline size</a> that would exactly include all of its columns.
		It may be approximated by: </p>
   <ul>
    <li> Laying out the element with column-spanning elements given <a class="css" data-link-type="propdesc" href="https://drafts.csswg.org/css-display-3/#propdef-display" id="ref-for-propdef-display">display: none</a>,
			and taking a inline-size that includes all the columns. 
    <li> Laying out all of the column-spanning elements into that resulting inline-size,
			and taking the resulting block-size. 
    <li> Subtracting that resulting block-size from the specified restraint,
			laying out the element without column-spanning elements again into this adjusted block-size,
			and taking the inline-size of all its columns as its <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size" id="ref-for-max-content-inline-size⑦">max-content inline size</a>. 
   </ul>
   <p> or by some more accurate method. </p>
   <p class="note" role="note"> This approximation can result in some slack,
		but avoids overflow in the most common cases,
		where the balanced height of the columns above spanning elements are approximately equal. </p>
   <p class="note" role="note"> In the common case of no column-spanning elements,
		this approximation collapses to simply doing a layout,
		and measuring the resulting columns. </p>
   <h3 class="heading settled" data-level="5.6" id="intrinsic-size-override"><span class="secno">5.6. </span><span class="content"> Overriding Intrinsic Sizes: the <a class="property" data-link-type="propdesc">intrinsic-*</a> properties</span><a class="self-link" href="#intrinsic-size-override"></a></h3>
   <table class="def propdef" data-link-for-hint="intrinsic-block-size">
    <tbody>
     <tr>
      <th>Name:
      <td><dfn class="css" data-dfn-type="property" data-export id="propdef-intrinsic-block-size">intrinsic-block-size<a class="self-link" href="#propdef-intrinsic-block-size"></a></dfn>, <dfn class="css" data-dfn-type="property" data-export id="propdef-intrinsic-inline-size">intrinsic-inline-size<a class="self-link" href="#propdef-intrinsic-inline-size"></a></dfn>, <dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-intrinsic-height">intrinsic-height</dfn>, <dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-intrinsic-width">intrinsic-width</dfn>
     <tr class="value">
      <th><a href="https://drafts.csswg.org/css-values/#value-defs">Value:</a>
      <td class="prod">legacy <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①">|</a> auto <span id="ref-for-comb-one②">|</span> <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#length-value" id="ref-for-length-value" title="Expands to: em | vb | ch | cm | vh | vi | in | ex | vw | ic | pt | px | lh | pc | rem | rlh | vmax | advance measure | vmin | mm | cap | q">&lt;length></a> 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#initial-values">Initial:</a>
      <td>legacy 
     <tr>
      <th>Applies to:
      <td>all elements except <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#non-replaced" id="ref-for-non-replaced">non-replaced</a> <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#inline" id="ref-for-inline">inlines</a> 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#inherited-property">Inherited:</a>
      <td>no 
     <tr>
      <th><a href="https://drafts.csswg.org/css-values/#percentages">Percentages:</a>
      <td>n/a 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#computed">Computed value:</a>
      <td>as specified, with <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage" id="ref-for-typedef-length-percentage①">&lt;length-percentage></a> values computed 
     <tr>
      <th>Canonical order:
      <td>per grammar 
     <tr>
      <th><a href="https://drafts.csswg.org/web-animations/#animation-type">Animation type:</a>
      <td>by computed value type 
   </table>
   <p>The <a class="property" data-link-type="propdesc">intrinsic-*</a> properties determine
	whether the <a data-link-type="dfn" href="#intrinsic-size" id="ref-for-intrinsic-size②">intrinsic sizes</a> of a box
	are calculated from sizes derived from its content
	(as defined by the rest of this chapter),
	or from a specified <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="explicit-intrinsic-inner-size">explicit intrinsic inner size</dfn>.
	Values are defined as follows:</p>
   <dl>
    <dt data-md><dfn class="dfn-paneled css" data-dfn-for="intrinsic-block-size, intrinsic-inline-size, intrinsic-height, intrinsic-width, intrinsic-size" data-dfn-type="value" data-export id="valdef-intrinsic-block-size-legacy">legacy</dfn>
    <dd data-md>
     <p>Does not specify an <a data-link-type="dfn" href="#explicit-intrinsic-inner-size" id="ref-for-explicit-intrinsic-inner-size③">explicit intrinsic inner size</a> of the box
in the relevant axis.
(Intrinsic sizes are thus determined in various ways
based on examining the content of the box as usual.
See <a href="#intrinsic">§ 5 Intrinsic Size Determination</a>, for example.)</p>
    <dt data-md><dfn class="css" data-dfn-for="intrinsic-block-size, intrinsic-inline-size, intrinsic-height, intrinsic-width, intrinsic-size" data-dfn-type="value" data-export id="valdef-intrinsic-block-size-auto">auto<a class="self-link" href="#valdef-intrinsic-block-size-auto"></a></dfn>
    <dd data-md>
     <p>If <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-overflow-3/#propdef-overflow" id="ref-for-propdef-overflow①">overflow</a> is not <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-overflow-3/#valdef-overflow-visible" id="ref-for-valdef-overflow-visible">visible</a> in the relevant axis,
specifies a zero <a data-link-type="dfn" href="#explicit-intrinsic-inner-size" id="ref-for-explicit-intrinsic-inner-size④">explicit intrinsic inner size</a> in that axis.
Otherwise same as <a class="css" data-link-type="maybe" href="#valdef-intrinsic-block-size-legacy" id="ref-for-valdef-intrinsic-block-size-legacy">legacy</a>.</p>
    <dt data-md><dfn class="css" data-dfn-for="intrinsic-block-size, intrinsic-inline-size, intrinsic-height, intrinsic-width, intrinsic-size" data-dfn-type="value" data-export id="valdef-intrinsic-block-size-length"><a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#length-value" id="ref-for-length-value①" title="Expands to: em | vb | ch | cm | vh | vi | in | ex | vw | ic | pt | px | lh | pc | rem | rlh | vmax | advance measure | vmin | mm | cap | q">&lt;length></a><a class="self-link" href="#valdef-intrinsic-block-size-length"></a></dfn>
    <dd data-md>
     <p>Specifies an <a data-link-type="dfn" href="#explicit-intrinsic-inner-size" id="ref-for-explicit-intrinsic-inner-size⑤">explicit intrinsic inner size</a> in the relevant axis.</p>
   </dl>
   <p class="note" role="note"><span>Note:</span> The value of <a class="property" data-link-type="propdesc">intrinsic-*</a> in one axis has no affect on the other axis.</p>
   <table class="def propdef" data-link-for-hint="intrinsic-size">
    <tbody>
     <tr>
      <th>Name:
      <td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-intrinsic-size">intrinsic-size</dfn>
     <tr class="value">
      <th><a href="https://drafts.csswg.org/css-values/#value-defs">Value:</a>
      <td class="prod"><a class="production" data-link-type="propdesc" href="#propdef-intrinsic-width" id="ref-for-propdef-intrinsic-width">&lt;'intrinsic-width'></a> <a class="production" data-link-type="propdesc" href="#propdef-intrinsic-height" id="ref-for-propdef-intrinsic-height">&lt;'intrinsic-height'></a><a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#mult-opt" id="ref-for-mult-opt">?</a> 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#initial-values">Initial:</a>
      <td>see individual properties 
     <tr>
      <th>Applies to:
      <td>see individual properties 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#inherited-property">Inherited:</a>
      <td>see individual properties 
     <tr>
      <th><a href="https://drafts.csswg.org/css-values/#percentages">Percentages:</a>
      <td>see individual properties 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#computed">Computed value:</a>
      <td>see individual properties 
     <tr>
      <th><a href="https://drafts.csswg.org/web-animations/#animation-type">Animation type:</a>
      <td>see individual properties 
     <tr>
      <th>Canonical order:
      <td>per grammar 
   </table>
   <p>The <a class="property" data-link-type="propdesc" href="#propdef-intrinsic-size" id="ref-for-propdef-intrinsic-size">intrinsic-size</a> property is a <a data-link-type="dfn" href="https://drafts.csswg.org/css-cascade-4/#shorthand-property" id="ref-for-shorthand-property">shorthand</a> for setting all the <a class="property" data-link-type="propdesc">intrinsic-*</a> properties in one declaration.</p>
   <p>The first value sets <a class="property" data-link-type="propdesc" href="#propdef-intrinsic-width" id="ref-for-propdef-intrinsic-width①">intrinsic-width</a>,
	and the second value sets <a class="property" data-link-type="propdesc" href="#propdef-intrinsic-height" id="ref-for-propdef-intrinsic-height①">intrinsic-height</a>.
	If the second value is omitted,
	it defaults to the first.</p>
   <p class="issue" id="issue-7c83a0cd"><a class="self-link" href="#issue-7c83a0cd"></a> When we figure out how to make other physical x/y shorthands,
	like <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size" id="ref-for-propdef-background-size">background-size</a>,
	work with logical sizes,
	we’ll apply the same logic here.</p>
   <h2 class="heading settled" data-level="6" id="intrinsic-contribution"><span class="secno">6. </span><span class="content"> Intrinsic Size Contributions</span><a class="self-link" href="#intrinsic-contribution"></a></h2>
   <p>A box’s <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution" id="ref-for-min-content-contribution①⓪">min-content contribution</a>/<a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution" id="ref-for-max-content-contribution⑦">max-content contribution</a> in each axis
	is the size of the content box
	of a hypothetical <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto" id="ref-for-valdef-width-auto⑦">auto</a>-sized float
	that contains only that box,
	if that hypothetical float’s containing block is zero-sized/infinitely-sized.</p>
   <p class="note" role="note"><span>Note:</span> This specification does not define precisely how to determine these sizes.
	Please refer to <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a>,
	the relevant CSS specification for that display type,
	the <a href="#percentage-sizing">rules for handling percentages</a> (below),
	and/or existing implementations
	for further details.</p>
   <h2 class="heading settled" data-level="7" id="extrinsic"><span class="secno">7. </span><span class="content"> Extrinsic Size Determination</span><a class="self-link" href="#extrinsic"></a></h2>
   <p>…</p>
   <h3 class="heading settled" data-level="7.1" id="stretch-fit-sizing"><span class="secno">7.1. </span><span class="content"> Stretch-fit Sizing</span><a class="self-link" href="#stretch-fit-sizing"></a></h3>
   <p>…</p>
   <h3 class="heading settled" data-level="7.2" id="contain-fit-sizing"><span class="secno">7.2. </span><span class="content"> Contain-fit Sizing: stretching while maintaining an aspect ratio</span><a class="self-link" href="#contain-fit-sizing"></a></h3>
   <p>Contain-fit sizing essentially applies stretch-fit sizing,
	but reduces the size of the box in one axis
	to maintain the box’s intrinsic aspect ratio,
	similar to the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-images-4/#valdef-object-fit-contain" id="ref-for-valdef-object-fit-contain">contain</a> keyword of the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-images-4/#propdef-object-fit" id="ref-for-propdef-object-fit">object-fit</a> and <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size" id="ref-for-propdef-background-size①">background-size</a> properties.</p>
   <p>First, a target rectangle is determined:</p>
   <ol>
    <li> The initial target rectangle is the size of the box’s containing block,
			with any indefinite size assumed as infinity.
			If both dimensions are indefinite,
			the initial target rectangle is set
			to match the outer edges of the box were it <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#stretch-fit-size" id="ref-for-stretch-fit-size">stretch-fit sized</a>. 
    <li> Next, if the box has a non-<a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-sizing-3/#valdef-max-width-none" id="ref-for-valdef-max-width-none①">none</a> <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-max-width" id="ref-for-propdef-max-width②">max-width</a> or <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-max-height" id="ref-for-propdef-max-height③">max-height</a>,
			the target rectangle is clamped in the affected dimension
			to less than or equal to the “maximum size” of the box’s margin box,
			i.e. the size its margin box would be
			if the box was sized at its max-width/height.
			(Note that, consistent with normal <a href="http://www.w3.org/TR/CSS2/visuren.html">box-sizing rules</a>,
			this “maximum size” is floored by the effects of the box’s <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-width" id="ref-for-propdef-min-width②">min-width</a>/<a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-min-height" id="ref-for-propdef-min-height④">min-height</a>.) 
    <li> Last, the target rectangle is reduced in one dimension
			by the minimum necessary for it to match the box’s intrinsic aspect ratio. 
   </ol>
   <p>The contain-fit size in each dimension is
	the size that would result from stretch-fitting into the target rectangle.</p>
   <p class="issue" id="issue-6e598fc0"><a class="self-link" href="#issue-6e598fc0"></a> Copy whatever stretch-fit ends up doing wrt margin collapsing.</p>
   <p class="issue" id="issue-9d61aaed"><a class="self-link" href="#issue-9d61aaed"></a> If there is a minimum size in one dimension
	that would cause overflow of the target rectangle if the aspect ratio were honored,
	do we honor the aspect ratio or skew the image?
	If the former, we need a step similar to #2 that applies the relevant minimums.</p>
   <h3 class="heading settled" data-level="7.3" id="percentage-sizing"><span class="secno">7.3. </span><span class="content"> Percentage Sizing</span><a class="self-link" href="#percentage-sizing"></a></h3>
   <p>…</p>
   <h2 class="no-num heading settled" id="changes"><span class="content"> Changes</span><a class="self-link" href="#changes"></a></h2>
   <p> Changes since the <a href="https://www.w3.org/TR/2012/WD-css3-sizing-20120927/">September 2012 Working Draft</a> include: </p>
   <ul>
    <li>Changed <code>fill</code> keyword to <code>stretch-fit</code>. 
    <li>Hooked up intrinsic sizes of replaced elements to the <a data-link-type="dfn" href="https://drafts.csswg.org/css-images-3/#default-sizing-algorithm" id="ref-for-default-sizing-algorithm">default sizing algorithm</a> in <a data-link-type="biblio" href="#biblio-css3-images">[CSS3-IMAGES]</a>. 
    <li>Specified that <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#extrinsic-sizing" id="ref-for-extrinsic-sizing">extrinsic sizing</a> treates <span class="css">auto</span> margins as zero. 
    <li>Clarified definition of <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#available" id="ref-for-available">available space</a>. 
    <li>Specified that percentages resolved against an intrinsic size of the parent computes falls back to auto sizing. 
    <li>Fixed bad wording wrt containing blocks in <a data-link-type="dfn" href="https://drafts.csswg.org/css-sizing-3/#stretch-fit-inline-size" id="ref-for-stretch-fit-inline-size">stretch-fit inline size</a> definition,
		    and specified that it is calculated <em>after</em> margin collapsing. 
    <li>Specified that an absolutely-positioned box’s containing block is always considered definite. 
    <li>Improved section on intrinsic sizing of multi-column containers. 
    <li>Cleaned up some terminology (“min-size” to “min-content size”, “measure” to “inline-size, “extent” to “block-size”). 
   </ul>
   <h2 class="no-num heading settled" id="acknowledgments"><span class="content"> Acknowledgments</span><a class="self-link" href="#acknowledgments"></a></h2>
   <p>Special thanks go to Aaron Gustafson, L. David Baron
	for their contributions to this module. </p>
   <h2 class="no-num heading settled" id="priv-sec"><span class="content"> Privacy and Security Considerations</span><a class="self-link" href="#priv-sec"></a></h2>
   <p>This specification introduces no new privacy or security considerations.</p>
  </main>
  <h2 class="no-ref no-num heading settled" id="conformance"><span class="content"> Conformance</span><a class="self-link" href="#conformance"></a></h2>
  <h3 class="heading settled" id="document-conventions"><span class="content"> Document conventions</span><a class="self-link" href="#document-conventions"></a></h3>
  <p>Conformance requirements are expressed with a combination of
	descriptive assertions and RFC 2119 terminology. The key words “MUST”,
	“MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”,
	“RECOMMENDED”, “MAY”, and “OPTIONAL” in the normative parts of this
	document are to be interpreted as described in RFC 2119.
	However, for readability, these words do not appear in all uppercase
	letters in this specification. </p>
  <p>All of the text of this specification is normative except sections
	explicitly marked as non-normative, examples, and notes. <a data-link-type="biblio" href="#biblio-rfc2119">[RFC2119]</a> </p>
  <p>Examples in this specification are introduced with the words “for example”
	or are set apart from the normative text with <code>class="example"</code>,
	like this: </p>
  <div class="example" id="example-ae2b6bc0">
   <a class="self-link" href="#example-ae2b6bc0"></a> 
   <p>This is an example of an informative example. </p>
  </div>
  <p>Informative notes begin with the word “Note” and are set apart from the
	normative text with <code>class="note"</code>, like this: </p>
  <p class="note" role="note">Note, this is an informative note. </p>
  <p>Advisements are normative sections styled to evoke special attention and are
	set apart from other normative text with <code>&lt;strong class="advisement"></code>, like
	this: <strong class="advisement"> UAs MUST provide an accessible alternative. </strong> </p>
  <h3 class="heading settled" id="conform-classes"><span class="content"> Conformance classes</span><a class="self-link" href="#conform-classes"></a></h3>
  <p>Conformance to this specification
	is defined for three conformance classes: </p>
  <dl>
   <dt>style sheet 
   <dd>A <a href="http://www.w3.org/TR/CSS2/conform.html#style-sheet">CSS
			style sheet</a>. 
   <dt>renderer 
   <dd>A <a href="http://www.w3.org/TR/CSS2/conform.html#user-agent">UA</a> that interprets the semantics of a style sheet and renders
			documents that use them. 
   <dt>authoring tool 
   <dd>A <a href="http://www.w3.org/TR/CSS2/conform.html#user-agent">UA</a> that writes a style sheet. 
  </dl>
  <p>A style sheet is conformant to this specification
	if all of its statements that use syntax defined in this module are valid
	according to the generic CSS grammar and the individual grammars of each
	feature defined in this module. </p>
  <p>A renderer is conformant to this specification
	if, in addition to interpreting the style sheet as defined by the
	appropriate specifications, it supports all the features defined
	by this specification by parsing them correctly
	and rendering the document accordingly. However, the inability of a
	UA to correctly render a document due to limitations of the device
	does not make the UA non-conformant. (For example, a UA is not
	required to render color on a monochrome monitor.) </p>
  <p>An authoring tool is conformant to this specification
	if it writes style sheets that are syntactically correct according to the
	generic CSS grammar and the individual grammars of each feature in
	this module, and meet all other conformance requirements of style sheets
	as described in this module. </p>
  <h3 class="heading settled" id="conform-responsible"><span class="content"> Requirements for Responsible Implementation of CSS</span><a class="self-link" href="#conform-responsible"></a></h3>
  <p>The following sections define several conformance requirements
		for implementing CSS responsibly,
		in a way that promotes interoperability in the present and future. </p>
  <h4 class="heading settled" id="conform-partial"><span class="content"> Partial Implementations</span><a class="self-link" href="#conform-partial"></a></h4>
  <p>So that authors can exploit the forward-compatible parsing rules to assign fallback values, <strong>CSS renderers <em>must</em> treat as invalid
		(and <a href="http://www.w3.org/TR/CSS2/conform.html#ignore">ignore as appropriate</a>)
		any at-rules, properties, property values, keywords, and other syntactic constructs
		for which they have no usable level of support</strong>.
		In particular, user agents <em>must not</em> selectively ignore
		unsupported property values and honor supported values in a single multi-value property declaration:
		if any value is considered invalid (as unsupported values must be),
		CSS requires that the entire declaration be ignored. </p>
  <h4 class="heading settled" id="conform-future-proofing"><span class="content"> Implementations of Unstable and Proprietary Features</span><a class="self-link" href="#conform-future-proofing"></a></h4>
  <p>To avoid clashes with future stable CSS features,
		the CSSWG recommends <a href="http://www.w3.org/TR/CSS/#future-proofing">following best practices</a> for the implementation of <a href="http://www.w3.org/TR/CSS/#unstable">unstable</a> features and <a href="http://www.w3.org/TR/CSS/#proprietary-extension">proprietary extensions</a> to CSS. </p>
  <h4 class="heading settled" id="conform-testing"><span class="content"> Implementations of CR-level Features</span><a class="self-link" href="#conform-testing"></a></h4>
  <p>Once a specification reaches the Candidate Recommendation stage,
		implementers should release an <a data-link-type="dfn" href="http://www.w3.org/TR/CSS/#vendor-prefix">unprefixed</a> implementation
		of any CR-level feature they can demonstrate
		to be correctly implemented according to spec,
		and should avoid exposing a prefixed variant of that feature. </p>
  <p>To establish and maintain the interoperability of CSS across
		implementations, the CSS Working Group requests that non-experimental
		CSS renderers submit an implementation report (and, if necessary, the
		testcases used for that implementation report) to the W3C before
		releasing an unprefixed implementation of any CSS features. Testcases
		submitted to W3C are subject to review and correction by the CSS
		Working Group. </p>
  <p>
   Further information on submitting testcases and implementation reports
		can be found from on the CSS Working Group’s website at <a href="http://www.w3.org/Style/CSS/Test/">http://www.w3.org/Style/CSS/Test/</a>.
		Questions should be directed to the <a href="http://lists.w3.org/Archives/Public/public-css-testsuite">public-css-testsuite@w3.org</a> mailing list. 
<script src="https://www.w3.org/scripts/TR/2016/fixup.js"></script>
  </p>
  <aside class="caniuse-status" data-deco data-dfn-id="box-sizing">
   <input class="caniuse-panel-btn" type="button" value="⋰">
   <p class="support"><b>Support:</b><span class="android yes"><span>Android Browser</span><span>4+</span></span><span class="baidu yes"><span>Baidu Browser</span><span>7.12+</span></span><span class="bb yes"><span>Blackberry Browser</span><span>10+</span></span><span class="chrome yes"><span>Chrome</span><span>10+</span></span><span class="and_chr yes"><span>Chrome for Android</span><span>74+</span></span><span class="edge yes"><span>Edge</span><span>12+</span></span><span class="firefox yes"><span>Firefox</span><span>29+</span></span><span class="and_ff yes"><span>Firefox for Android</span><span>66+</span></span><span class="ie yes"><span>IE</span><span>8+</span></span><span class="ie_mob yes"><span>IE Mobile</span><span>10+</span></span><span class="kaios yes"><span>KaiOS Browser</span><span>2.5+</span></span><span class="opera yes"><span>Opera</span><span>9.5+</span></span><span class="op_mini yes"><span>Opera Mini</span><span>All</span></span><span class="op_mob yes"><span>Opera Mobile</span><span>10+</span></span><span class="and_qq yes"><span>QQ Browser</span><span>1.2+</span></span><span class="safari yes"><span>Safari</span><span>5.1+</span></span><span class="samsung yes"><span>Samsung Internet</span><span>4+</span></span><span class="and_uc yes"><span>UC Browser for Android</span><span>11.8+</span></span><span class="ios_saf yes"><span>iOS Safari</span><span>5.0+</span></span></p>
   <p class="caniuse">Source: <a href="https://caniuse.com/#feat=css3-boxsizing">caniuse.com</a> as of 2019-06-04</p>
  </aside>
  <h2 class="no-num no-ref heading settled" id="index"><span class="content">Index</span><a class="self-link" href="#index"></a></h2>
  <h3 class="no-num no-ref heading settled" id="index-defined-here"><span class="content">Terms defined by this specification</span><a class="self-link" href="#index-defined-here"></a></h3>
  <ul class="index">
   <li><a href="#propdef-aspect-ratio">aspect-ratio</a><span>, in §4.1</span>
   <li>
    auto
    <ul>
     <li><a href="#valdef-aspect-ratio-auto">value for aspect-ratio</a><span>, in §4.1</span>
     <li><a href="#valdef-intrinsic-block-size-auto">value for intrinsic-block-size, intrinsic-inline-size, intrinsic-height, intrinsic-width, intrinsic-size</a><span>, in §5.6</span>
    </ul>
   <li><a href="#explicit-intrinsic-inner-size">explicit intrinsic inner size</a><span>, in §5.6</span>
   <li><a href="#propdef-intrinsic-block-size">intrinsic-block-size</a><span>, in §5.6</span>
   <li><a href="#propdef-intrinsic-height">intrinsic-height</a><span>, in §5.6</span>
   <li><a href="#propdef-intrinsic-inline-size">intrinsic-inline-size</a><span>, in §5.6</span>
   <li><a href="#propdef-intrinsic-size">intrinsic-size</a><span>, in §5.6</span>
   <li><a href="#intrinsic-size">intrinsic size</a><span>, in §5</span>
   <li><a href="#constraints">intrinsic size constraint</a><span>, in §2.2</span>
   <li><a href="#propdef-intrinsic-width">intrinsic-width</a><span>, in §5.6</span>
   <li><a href="#valdef-intrinsic-block-size-legacy">legacy</a><span>, in §5.6</span>
   <li><a href="#valdef-intrinsic-block-size-length">&lt;length></a><span>, in §5.6</span>
   <li><a href="#max-size-properties">max size property</a><span>, in §3.1.2</span>
   <li><a href="#min-size-properties">min size property</a><span>, in §3.1.1</span>
   <li><a href="#preferred-aspect-ratio">preferred aspect ratio</a><span>, in §4.1</span>
   <li><a href="#preferred-size-properties">preferred size property</a><span>, in §3.1</span>
   <li><a href="#valdef-aspect-ratio-ratio">&lt;ratio></a><span>, in §4.1</span>
   <li><a href="#ratio-dependent-axis">ratio-dependent axis</a><span>, in §4.1</span>
  </ul>
  <aside class="dfn-panel" data-for="term-for-propdef-column-gap">
   <a href="https://drafts.csswg.org/css-align-3/#propdef-column-gap">https://drafts.csswg.org/css-align-3/#propdef-column-gap</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-column-gap">5.5.1. 
Min-content Sizes in Multi-column Layout</a>
    <li><a href="#ref-for-propdef-column-gap①">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a> <a href="#ref-for-propdef-column-gap②">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-background-size">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size">https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-background-size">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
    <li><a href="#ref-for-propdef-background-size①">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-content-box">
   <a href="https://drafts.csswg.org/css-box-3/#content-box">https://drafts.csswg.org/css-box-3/#content-box</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-content-box">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-shorthand-property">
   <a href="https://drafts.csswg.org/css-cascade-4/#shorthand-property">https://drafts.csswg.org/css-cascade-4/#shorthand-property</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-shorthand-property">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-block-container">
   <a href="https://drafts.csswg.org/css-display-3/#block-container">https://drafts.csswg.org/css-display-3/#block-container</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-block-container">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-block-container①">(2)</a> <a href="#ref-for-block-container②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-block-level-box">
   <a href="https://drafts.csswg.org/css-display-3/#block-level-box">https://drafts.csswg.org/css-display-3/#block-level-box</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-block-level-box">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-block-level-box①">(2)</a> <a href="#ref-for-block-level-box②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-display">
   <a href="https://drafts.csswg.org/css-display-3/#propdef-display">https://drafts.csswg.org/css-display-3/#propdef-display</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-display">5.5.3. 
Max-content Sizes in Constrained-height Multi-column Layout</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-inline">
   <a href="https://drafts.csswg.org/css-display-3/#inline">https://drafts.csswg.org/css-display-3/#inline</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-inline">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-inline-box">
   <a href="https://drafts.csswg.org/css-display-3/#inline-box">https://drafts.csswg.org/css-display-3/#inline-box</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-inline-box">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-non-replaced">
   <a href="https://drafts.csswg.org/css-display-3/#non-replaced">https://drafts.csswg.org/css-display-3/#non-replaced</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-non-replaced">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-replaced-element">
   <a href="https://drafts.csswg.org/css-display-3/#replaced-element">https://drafts.csswg.org/css-display-3/#replaced-element</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-replaced-element">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-replaced-element①">(2)</a>
    <li><a href="#ref-for-replaced-element②">4.1.1. 
Automatic Content-based Minimum Sizes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-flex-basis-content">
   <a href="https://drafts.csswg.org/css-flexbox-1/#valdef-flex-basis-content">https://drafts.csswg.org/css-flexbox-1/#valdef-flex-basis-content</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-flex-basis-content">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-valdef-flex-basis-content①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-cross-size">
   <a href="https://drafts.csswg.org/css-flexbox-1/#cross-size">https://drafts.csswg.org/css-flexbox-1/#cross-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-cross-size">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-flex-item">
   <a href="https://drafts.csswg.org/css-flexbox-1/#flex-item">https://drafts.csswg.org/css-flexbox-1/#flex-item</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-flex-item">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-object-fit-contain">
   <a href="https://drafts.csswg.org/css-images-4/#valdef-object-fit-contain">https://drafts.csswg.org/css-images-4/#valdef-object-fit-contain</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-object-fit-contain">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-object-fit">
   <a href="https://drafts.csswg.org/css-images-4/#propdef-object-fit">https://drafts.csswg.org/css-images-4/#propdef-object-fit</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-object-fit">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-max-block-size">
   <a href="https://drafts.csswg.org/css-logical-1/#propdef-max-block-size">https://drafts.csswg.org/css-logical-1/#propdef-max-block-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-max-block-size">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-min-block-size">
   <a href="https://drafts.csswg.org/css-logical-1/#propdef-min-block-size">https://drafts.csswg.org/css-logical-1/#propdef-min-block-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-min-block-size">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-overflow">
   <a href="https://drafts.csswg.org/css-overflow-3/#propdef-overflow">https://drafts.csswg.org/css-overflow-3/#propdef-overflow</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-overflow">4.1.1. 
Automatic Content-based Minimum Sizes</a>
    <li><a href="#ref-for-propdef-overflow①">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-scroll-container">
   <a href="https://drafts.csswg.org/css-overflow-3/#scroll-container">https://drafts.csswg.org/css-overflow-3/#scroll-container</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-scroll-container">4.1.1. 
Automatic Content-based Minimum Sizes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-overflow-visible">
   <a href="https://drafts.csswg.org/css-overflow-3/#valdef-overflow-visible">https://drafts.csswg.org/css-overflow-3/#valdef-overflow-visible</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-overflow-visible">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-width-auto">
   <a href="https://drafts.csswg.org/css-sizing-3/#valdef-width-auto">https://drafts.csswg.org/css-sizing-3/#valdef-width-auto</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-width-auto">3.2. 
Sizing Values: the &lt;length-percentage>, auto | none, min-content, max-content, and fit-content() values</a>
    <li><a href="#ref-for-valdef-width-auto①">3.2.1. 
“Behaving as auto”</a>
    <li><a href="#ref-for-valdef-width-auto②">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-valdef-width-auto③">(2)</a> <a href="#ref-for-valdef-width-auto④">(3)</a>
    <li><a href="#ref-for-valdef-width-auto⑤">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-valdef-width-auto⑥">(2)</a>
    <li><a href="#ref-for-valdef-width-auto⑦">6. 
Intrinsic Size Contributions</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-automatic-minimum-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#automatic-minimum-size">https://drafts.csswg.org/css-sizing-3/#automatic-minimum-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-automatic-minimum-size">4.1.1. 
Automatic Content-based Minimum Sizes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-automatic-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#automatic-size">https://drafts.csswg.org/css-sizing-3/#automatic-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-automatic-size">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-automatic-size①">(2)</a> <a href="#ref-for-automatic-size②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-available">
   <a href="https://drafts.csswg.org/css-sizing-3/#available">https://drafts.csswg.org/css-sizing-3/#available</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-available"> Changes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-box-sizing">
   <a href="https://drafts.csswg.org/css-sizing-3/#propdef-box-sizing">https://drafts.csswg.org/css-sizing-3/#propdef-box-sizing</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-box-sizing">3.3. 
Box Edges for Sizing: the box-sizing property</a>
    <li><a href="#ref-for-propdef-box-sizing①">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-definite">
   <a href="https://drafts.csswg.org/css-sizing-3/#definite">https://drafts.csswg.org/css-sizing-3/#definite</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-definite">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-definite①">(2)</a>
    <li><a href="#ref-for-definite②">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-definite③">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-definite">
   <a href="https://drafts.csswg.org/css-sizing-3/#definite">https://drafts.csswg.org/css-sizing-3/#definite</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-definite">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-definite①">(2)</a>
    <li><a href="#ref-for-definite②">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-definite③">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-extrinsic-sizing">
   <a href="https://drafts.csswg.org/css-sizing-3/#extrinsic-sizing">https://drafts.csswg.org/css-sizing-3/#extrinsic-sizing</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-extrinsic-sizing"> Changes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-width-max-content">
   <a href="https://drafts.csswg.org/css-sizing-3/#valdef-width-max-content">https://drafts.csswg.org/css-sizing-3/#valdef-width-max-content</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-width-max-content">3.2. 
Sizing Values: the &lt;length-percentage>, auto | none, min-content, max-content, and fit-content() values</a>
    <li><a href="#ref-for-valdef-width-max-content①">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-valdef-width-max-content②">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-content-block-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-content-block-size">https://drafts.csswg.org/css-sizing-3/#max-content-block-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-content-block-size">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a>
    <li><a href="#ref-for-max-content-block-size①">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-content-contribution">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution">https://drafts.csswg.org/css-sizing-3/#max-content-contribution</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-content-contribution">5.1. 
Intrinsic Sizes of Replaced Elements</a>
    <li><a href="#ref-for-max-content-contribution①">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-max-content-contribution②">(2)</a>
    <li><a href="#ref-for-max-content-contribution③">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-max-content-contribution④">(2)</a> <a href="#ref-for-max-content-contribution⑤">(3)</a>
    <li><a href="#ref-for-max-content-contribution⑥">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a>
    <li><a href="#ref-for-max-content-contribution⑦">6. 
Intrinsic Size Contributions</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-content-constraint">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-content-constraint">https://drafts.csswg.org/css-sizing-3/#max-content-constraint</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-content-constraint">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-content-contribution">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution">https://drafts.csswg.org/css-sizing-3/#max-content-contribution</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-content-contribution">5.1. 
Intrinsic Sizes of Replaced Elements</a>
    <li><a href="#ref-for-max-content-contribution①">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-max-content-contribution②">(2)</a>
    <li><a href="#ref-for-max-content-contribution③">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-max-content-contribution④">(2)</a> <a href="#ref-for-max-content-contribution⑤">(3)</a>
    <li><a href="#ref-for-max-content-contribution⑥">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a>
    <li><a href="#ref-for-max-content-contribution⑦">6. 
Intrinsic Size Contributions</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-content-inline-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-content-inline-size">https://drafts.csswg.org/css-sizing-3/#max-content-inline-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-content-inline-size">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-max-content-inline-size①">(2)</a>
    <li><a href="#ref-for-max-content-inline-size②">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-max-content-inline-size③">(2)</a>
    <li><a href="#ref-for-max-content-inline-size④">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a> <a href="#ref-for-max-content-inline-size⑤">(2)</a>
    <li><a href="#ref-for-max-content-inline-size⑥">5.5.3. 
Max-content Sizes in Constrained-height Multi-column Layout</a> <a href="#ref-for-max-content-inline-size⑦">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-content-contribution">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-content-contribution">https://drafts.csswg.org/css-sizing-3/#max-content-contribution</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-content-contribution">5.1. 
Intrinsic Sizes of Replaced Elements</a>
    <li><a href="#ref-for-max-content-contribution①">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-max-content-contribution②">(2)</a>
    <li><a href="#ref-for-max-content-contribution③">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-max-content-contribution④">(2)</a> <a href="#ref-for-max-content-contribution⑤">(3)</a>
    <li><a href="#ref-for-max-content-contribution⑥">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a>
    <li><a href="#ref-for-max-content-contribution⑦">6. 
Intrinsic Size Contributions</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-content">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-content">https://drafts.csswg.org/css-sizing-3/#max-content</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-content">5.1. 
Intrinsic Sizes of Replaced Elements</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-max-width">
   <a href="https://drafts.csswg.org/css-sizing-3/#max-width">https://drafts.csswg.org/css-sizing-3/#max-width</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-max-width">4.1.1. 
Automatic Content-based Minimum Sizes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-width-min-content">
   <a href="https://drafts.csswg.org/css-sizing-3/#valdef-width-min-content">https://drafts.csswg.org/css-sizing-3/#valdef-width-min-content</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-width-min-content">3.2. 
Sizing Values: the &lt;length-percentage>, auto | none, min-content, max-content, and fit-content() values</a>
    <li><a href="#ref-for-valdef-width-min-content①">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
    <li><a href="#ref-for-valdef-width-min-content②">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-valdef-width-min-content③">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-min-content-block-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#min-content-block-size">https://drafts.csswg.org/css-sizing-3/#min-content-block-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-min-content-block-size">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a>
    <li><a href="#ref-for-min-content-block-size①">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-min-content-contribution">
   <a href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution">https://drafts.csswg.org/css-sizing-3/#min-content-contribution</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-min-content-contribution">5.1. 
Intrinsic Sizes of Replaced Elements</a>
    <li><a href="#ref-for-min-content-contribution①">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-min-content-contribution②">(2)</a>
    <li><a href="#ref-for-min-content-contribution③">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-min-content-contribution④">(2)</a> <a href="#ref-for-min-content-contribution⑤">(3)</a> <a href="#ref-for-min-content-contribution⑥">(4)</a>
    <li><a href="#ref-for-min-content-contribution⑦">5.5.1. 
Min-content Sizes in Multi-column Layout</a> <a href="#ref-for-min-content-contribution⑧">(2)</a>
    <li><a href="#ref-for-min-content-contribution⑨">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a>
    <li><a href="#ref-for-min-content-contribution①⓪">6. 
Intrinsic Size Contributions</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-min-content-contribution">
   <a href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution">https://drafts.csswg.org/css-sizing-3/#min-content-contribution</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-min-content-contribution">5.1. 
Intrinsic Sizes of Replaced Elements</a>
    <li><a href="#ref-for-min-content-contribution①">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-min-content-contribution②">(2)</a>
    <li><a href="#ref-for-min-content-contribution③">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-min-content-contribution④">(2)</a> <a href="#ref-for-min-content-contribution⑤">(3)</a> <a href="#ref-for-min-content-contribution⑥">(4)</a>
    <li><a href="#ref-for-min-content-contribution⑦">5.5.1. 
Min-content Sizes in Multi-column Layout</a> <a href="#ref-for-min-content-contribution⑧">(2)</a>
    <li><a href="#ref-for-min-content-contribution⑨">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a>
    <li><a href="#ref-for-min-content-contribution①⓪">6. 
Intrinsic Size Contributions</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-min-content-inline-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#min-content-inline-size">https://drafts.csswg.org/css-sizing-3/#min-content-inline-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-min-content-inline-size">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-min-content-inline-size①">(2)</a>
    <li><a href="#ref-for-min-content-inline-size②">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-min-content-inline-size③">(2)</a>
    <li><a href="#ref-for-min-content-inline-size④">5.5.1. 
Min-content Sizes in Multi-column Layout</a> <a href="#ref-for-min-content-inline-size⑤">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-min-content-contribution">
   <a href="https://drafts.csswg.org/css-sizing-3/#min-content-contribution">https://drafts.csswg.org/css-sizing-3/#min-content-contribution</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-min-content-contribution">5.1. 
Intrinsic Sizes of Replaced Elements</a>
    <li><a href="#ref-for-min-content-contribution①">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-min-content-contribution②">(2)</a>
    <li><a href="#ref-for-min-content-contribution③">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-min-content-contribution④">(2)</a> <a href="#ref-for-min-content-contribution⑤">(3)</a> <a href="#ref-for-min-content-contribution⑥">(4)</a>
    <li><a href="#ref-for-min-content-contribution⑦">5.5.1. 
Min-content Sizes in Multi-column Layout</a> <a href="#ref-for-min-content-contribution⑧">(2)</a>
    <li><a href="#ref-for-min-content-contribution⑨">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a>
    <li><a href="#ref-for-min-content-contribution①⓪">6. 
Intrinsic Size Contributions</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-min-content">
   <a href="https://drafts.csswg.org/css-sizing-3/#min-content">https://drafts.csswg.org/css-sizing-3/#min-content</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-min-content">4.1.1. 
Automatic Content-based Minimum Sizes</a>
    <li><a href="#ref-for-min-content①">5.1. 
Intrinsic Sizes of Replaced Elements</a> <a href="#ref-for-min-content②">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-max-width-none">
   <a href="https://drafts.csswg.org/css-sizing-3/#valdef-max-width-none">https://drafts.csswg.org/css-sizing-3/#valdef-max-width-none</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-max-width-none">3.2. 
Sizing Values: the &lt;length-percentage>, auto | none, min-content, max-content, and fit-content() values</a>
    <li><a href="#ref-for-valdef-max-width-none①">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-preferred-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#preferred-size">https://drafts.csswg.org/css-sizing-3/#preferred-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-preferred-size">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-stretch-fit-inline-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#stretch-fit-inline-size">https://drafts.csswg.org/css-sizing-3/#stretch-fit-inline-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-stretch-fit-inline-size"> Changes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-stretch-fit-size">
   <a href="https://drafts.csswg.org/css-sizing-3/#stretch-fit-size">https://drafts.csswg.org/css-sizing-3/#stretch-fit-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-stretch-fit-size">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-length-value">
   <a href="https://drafts.csswg.org/css-values-3/#length-value">https://drafts.csswg.org/css-values-3/#length-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-length-value">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a> <a href="#ref-for-length-value①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-typedef-length-percentage">
   <a href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage">https://drafts.csswg.org/css-values-4/#typedef-length-percentage</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-length-percentage">3.2. 
Sizing Values: the &lt;length-percentage>, auto | none, min-content, max-content, and fit-content() values</a>
    <li><a href="#ref-for-typedef-length-percentage①">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-mult-opt">
   <a href="https://drafts.csswg.org/css-values-4/#mult-opt">https://drafts.csswg.org/css-values-4/#mult-opt</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-mult-opt">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-css-wide-keywords">
   <a href="https://drafts.csswg.org/css-values-4/#css-wide-keywords">https://drafts.csswg.org/css-values-4/#css-wide-keywords</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-css-wide-keywords">1.2. 
Values</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-comb-one">
   <a href="https://drafts.csswg.org/css-values-4/#comb-one">https://drafts.csswg.org/css-values-4/#comb-one</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-comb-one">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
    <li><a href="#ref-for-comb-one①">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a> <a href="#ref-for-comb-one②">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-block-size">
   <a href="https://drafts.csswg.org/css-writing-modes-4/#block-size">https://drafts.csswg.org/css-writing-modes-4/#block-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-block-size">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-block-size①">(2)</a>
    <li><a href="#ref-for-block-size②">5.5.3. 
Max-content Sizes in Constrained-height Multi-column Layout</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-block-axis">
   <a href="https://drafts.csswg.org/css-writing-modes-4/#block-axis">https://drafts.csswg.org/css-writing-modes-4/#block-axis</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-block-axis">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-horizontal-writing-mode">
   <a href="https://drafts.csswg.org/css-writing-modes-4/#horizontal-writing-mode">https://drafts.csswg.org/css-writing-modes-4/#horizontal-writing-mode</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-horizontal-writing-mode">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-inline-size">
   <a href="https://drafts.csswg.org/css-writing-modes-4/#inline-size">https://drafts.csswg.org/css-writing-modes-4/#inline-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-inline-size">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-inline-size①">(2)</a> <a href="#ref-for-inline-size②">(3)</a>
    <li><a href="#ref-for-inline-size③">5.5.3. 
Max-content Sizes in Constrained-height Multi-column Layout</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-inline-axis">
   <a href="https://drafts.csswg.org/css-writing-modes-4/#inline-axis">https://drafts.csswg.org/css-writing-modes-4/#inline-axis</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-inline-axis">5.2. 
Intrinsic Sizes of Non-Replaced Inlines</a> <a href="#ref-for-inline-axis①">(2)</a>
    <li><a href="#ref-for-inline-axis②">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a> <a href="#ref-for-inline-axis③">(2)</a> <a href="#ref-for-inline-axis④">(3)</a> <a href="#ref-for-inline-axis⑤">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-height">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-height">https://drafts.csswg.org/css2/visudet.html#propdef-height</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-height">1.1. 
Module interactions</a>
    <li><a href="#ref-for-propdef-height①">3.1.1. 
Preferred Size Properties: the width and height properties</a>
    <li><a href="#ref-for-propdef-height②">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
    <li><a href="#ref-for-propdef-height③">5.3. 
Intrinsic Sizes of Non-Replaced Blocks</a>
    <li><a href="#ref-for-propdef-height④">5.5.3. 
Max-content Sizes in Constrained-height Multi-column Layout</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-max-height">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-max-height">https://drafts.csswg.org/css2/visudet.html#propdef-max-height</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-max-height">1.1. 
Module interactions</a>
    <li><a href="#ref-for-propdef-max-height①">3.1.3. 
Maximum Size Properties: the max-width and max-height properties</a>
    <li><a href="#ref-for-propdef-max-height②">5.5.3. 
Max-content Sizes in Constrained-height Multi-column Layout</a>
    <li><a href="#ref-for-propdef-max-height③">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-max-width">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-max-width">https://drafts.csswg.org/css2/visudet.html#propdef-max-width</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-max-width">1.1. 
Module interactions</a>
    <li><a href="#ref-for-propdef-max-width①">3.1.3. 
Maximum Size Properties: the max-width and max-height properties</a>
    <li><a href="#ref-for-propdef-max-width②">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-min-height">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-min-height">https://drafts.csswg.org/css2/visudet.html#propdef-min-height</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-min-height">1.1. 
Module interactions</a>
    <li><a href="#ref-for-propdef-min-height①">3.1.2. 
Minimum Size Properties: the min-width and min-height properties</a>
    <li><a href="#ref-for-propdef-min-height②">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
    <li><a href="#ref-for-propdef-min-height③">4.1.1. 
Automatic Content-based Minimum Sizes</a>
    <li><a href="#ref-for-propdef-min-height④">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-min-width">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-min-width">https://drafts.csswg.org/css2/visudet.html#propdef-min-width</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-min-width">1.1. 
Module interactions</a>
    <li><a href="#ref-for-propdef-min-width①">3.1.2. 
Minimum Size Properties: the min-width and min-height properties</a>
    <li><a href="#ref-for-propdef-min-width②">7.2. 
Contain-fit Sizing: stretching while maintaining an aspect ratio</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-width">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-width">https://drafts.csswg.org/css2/visudet.html#propdef-width</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-width">1.1. 
Module interactions</a>
    <li><a href="#ref-for-propdef-width①">3.1.1. 
Preferred Size Properties: the width and height properties</a>
    <li><a href="#ref-for-propdef-width②">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-default-sizing-algorithm">
   <a href="https://drafts.csswg.org/css-images-3/#default-sizing-algorithm">https://drafts.csswg.org/css-images-3/#default-sizing-algorithm</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-default-sizing-algorithm"> Changes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-intrinsic-aspect-ratio">
   <a href="https://drafts.csswg.org/css-images-3/#intrinsic-aspect-ratio">https://drafts.csswg.org/css-images-3/#intrinsic-aspect-ratio</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-intrinsic-aspect-ratio">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-intrinsic-aspect-ratio①">(2)</a> <a href="#ref-for-intrinsic-aspect-ratio②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-column-width-auto">
   <a href="https://drafts.csswg.org/css-multicol-1/#valdef-column-width-auto">https://drafts.csswg.org/css-multicol-1/#valdef-column-width-auto</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-column-width-auto">5.5.1. 
Min-content Sizes in Multi-column Layout</a> <a href="#ref-for-valdef-column-width-auto①">(2)</a>
    <li><a href="#ref-for-valdef-column-width-auto②">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-column-count">
   <a href="https://drafts.csswg.org/css-multicol-1/#propdef-column-count">https://drafts.csswg.org/css-multicol-1/#propdef-column-count</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-column-count">5.5.1. 
Min-content Sizes in Multi-column Layout</a> <a href="#ref-for-propdef-column-count①">(2)</a>
    <li><a href="#ref-for-propdef-column-count②">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a> <a href="#ref-for-propdef-column-count③">(2)</a> <a href="#ref-for-propdef-column-count④">(3)</a> <a href="#ref-for-propdef-column-count⑤">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-column-width">
   <a href="https://drafts.csswg.org/css-multicol-1/#propdef-column-width">https://drafts.csswg.org/css-multicol-1/#propdef-column-width</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-column-width">1.1. 
Module interactions</a>
    <li><a href="#ref-for-propdef-column-width①">5.5.1. 
Min-content Sizes in Multi-column Layout</a> <a href="#ref-for-propdef-column-width②">(2)</a> <a href="#ref-for-propdef-column-width③">(3)</a>
    <li><a href="#ref-for-propdef-column-width④">5.5.2. 
Max-content Sizes in Unconstrained-height Multi-column Layout</a> <a href="#ref-for-propdef-column-width⑤">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-the-iframe-element">
   <a href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element">https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-the-iframe-element">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-typedef-ratio">
   <a href="https://drafts.csswg.org/mediaqueries-4/#typedef-ratio">https://drafts.csswg.org/mediaqueries-4/#typedef-ratio</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-ratio">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-typedef-ratio①">(2)</a>
   </ul>
  </aside>
  <h3 class="no-num no-ref heading settled" id="index-defined-elsewhere"><span class="content">Terms defined by reference</span><a class="self-link" href="#index-defined-elsewhere"></a></h3>
  <ul class="index">
   <li>
    <a data-link-type="biblio">[css-align-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-column-gap" style="color:initial">column-gap</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-backgrounds-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-background-size" style="color:initial">background-size</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-box-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-content-box" style="color:initial">content box</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-cascade-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-shorthand-property" style="color:initial">shorthand</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-display-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-block-container" style="color:initial">block container box</span>
     <li><span class="dfn-paneled" id="term-for-block-level-box" style="color:initial">block-level box</span>
     <li><span class="dfn-paneled" id="term-for-propdef-display" style="color:initial">display</span>
     <li><span class="dfn-paneled" id="term-for-inline" style="color:initial">inline</span>
     <li><span class="dfn-paneled" id="term-for-inline-box" style="color:initial">inline box</span>
     <li><span class="dfn-paneled" id="term-for-non-replaced" style="color:initial">non-replaced</span>
     <li><span class="dfn-paneled" id="term-for-replaced-element" style="color:initial">replaced element</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-flexbox-1]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valdef-flex-basis-content" style="color:initial">content</span>
     <li><span class="dfn-paneled" id="term-for-cross-size" style="color:initial">cross size</span>
     <li><span class="dfn-paneled" id="term-for-flex-item" style="color:initial">flex item</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-images-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valdef-object-fit-contain" style="color:initial">contain</span>
     <li><span class="dfn-paneled" id="term-for-propdef-object-fit" style="color:initial">object-fit</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-logical-1]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-max-block-size" style="color:initial">max-block-size</span>
     <li><span class="dfn-paneled" id="term-for-propdef-min-block-size" style="color:initial">min-block-size</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-overflow-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-overflow" style="color:initial">overflow</span>
     <li><span class="dfn-paneled" id="term-for-scroll-container" style="color:initial">scroll container</span>
     <li><span class="dfn-paneled" id="term-for-valdef-overflow-visible" style="color:initial">visible</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-sizing-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valdef-width-auto" style="color:initial">auto</span>
     <li><span class="dfn-paneled" id="term-for-automatic-minimum-size" style="color:initial">automatic minimum size</span>
     <li><span class="dfn-paneled" id="term-for-automatic-size" style="color:initial">automatic size</span>
     <li><span class="dfn-paneled" id="term-for-available" style="color:initial">available space</span>
     <li><span class="dfn-paneled" id="term-for-propdef-box-sizing" style="color:initial">box-sizing</span>
     <li><span class="dfn-paneled" id="term-for-definite" style="color:initial">definite</span>
     <li><span class="dfn-paneled" id="term-for-definite①" style="color:initial">definite size</span>
     <li><span class="dfn-paneled" id="term-for-extrinsic-sizing" style="color:initial">extrinsic sizing</span>
     <li><span class="dfn-paneled" id="term-for-valdef-width-max-content" style="color:initial">max-content <small>(for width)</small></span>
     <li><span class="dfn-paneled" id="term-for-max-content-block-size" style="color:initial">max-content block size</span>
     <li><span class="dfn-paneled" id="term-for-max-content-contribution" style="color:initial">max-content block-size contribution</span>
     <li><span class="dfn-paneled" id="term-for-max-content-constraint" style="color:initial">max-content constraint</span>
     <li><span class="dfn-paneled" id="term-for-max-content-contribution①" style="color:initial">max-content contribution</span>
     <li><span class="dfn-paneled" id="term-for-max-content-inline-size" style="color:initial">max-content inline size</span>
     <li><span class="dfn-paneled" id="term-for-max-content-contribution②" style="color:initial">max-content inline-size contribution</span>
     <li><span class="dfn-paneled" id="term-for-max-content" style="color:initial">max-content size</span>
     <li><span class="dfn-paneled" id="term-for-max-width" style="color:initial">maximum size</span>
     <li><span class="dfn-paneled" id="term-for-valdef-width-min-content" style="color:initial">min-content <small>(for width)</small></span>
     <li><span class="dfn-paneled" id="term-for-min-content-block-size" style="color:initial">min-content block size</span>
     <li><span class="dfn-paneled" id="term-for-min-content-contribution" style="color:initial">min-content block-size contribution</span>
     <li><span class="dfn-paneled" id="term-for-min-content-contribution①" style="color:initial">min-content contribution</span>
     <li><span class="dfn-paneled" id="term-for-min-content-inline-size" style="color:initial">min-content inline size</span>
     <li><span class="dfn-paneled" id="term-for-min-content-contribution②" style="color:initial">min-content inline-size contribution</span>
     <li><span class="dfn-paneled" id="term-for-min-content" style="color:initial">min-content size</span>
     <li><span class="dfn-paneled" id="term-for-valdef-max-width-none" style="color:initial">none</span>
     <li><span class="dfn-paneled" id="term-for-preferred-size" style="color:initial">preferred size</span>
     <li><span class="dfn-paneled" id="term-for-stretch-fit-inline-size" style="color:initial">stretch-fit inline size</span>
     <li><span class="dfn-paneled" id="term-for-stretch-fit-size" style="color:initial">stretch-fit size</span>
    </ul>
   <li>
    <a data-link-type="biblio">[CSS-VALUES-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-length-value" style="color:initial">&lt;length></span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-values-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-typedef-length-percentage" style="color:initial">&lt;length-percentage></span>
     <li><span class="dfn-paneled" id="term-for-mult-opt" style="color:initial">?</span>
     <li><span class="dfn-paneled" id="term-for-css-wide-keywords" style="color:initial">css-wide keywords</span>
     <li><span class="dfn-paneled" id="term-for-comb-one" style="color:initial">|</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-writing-modes-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-block-size" style="color:initial">block size</span>
     <li><span class="dfn-paneled" id="term-for-block-axis" style="color:initial">block-axis</span>
     <li><span class="dfn-paneled" id="term-for-horizontal-writing-mode" style="color:initial">horizontal writing mode</span>
     <li><span class="dfn-paneled" id="term-for-inline-size" style="color:initial">inline size</span>
     <li><span class="dfn-paneled" id="term-for-inline-axis" style="color:initial">inline-axis</span>
    </ul>
   <li>
    <a data-link-type="biblio">[CSS2]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-height" style="color:initial">height</span>
     <li><span class="dfn-paneled" id="term-for-propdef-max-height" style="color:initial">max-height</span>
     <li><span class="dfn-paneled" id="term-for-propdef-max-width" style="color:initial">max-width</span>
     <li><span class="dfn-paneled" id="term-for-propdef-min-height" style="color:initial">min-height</span>
     <li><span class="dfn-paneled" id="term-for-propdef-min-width" style="color:initial">min-width</span>
     <li><span class="dfn-paneled" id="term-for-propdef-width" style="color:initial">width</span>
    </ul>
   <li>
    <a data-link-type="biblio">[CSS3-IMAGES]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-default-sizing-algorithm" style="color:initial">default sizing algorithm</span>
     <li><span class="dfn-paneled" id="term-for-intrinsic-aspect-ratio" style="color:initial">intrinsic aspect ratio</span>
    </ul>
   <li>
    <a data-link-type="biblio">[CSS3COL]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valdef-column-width-auto" style="color:initial">auto <small>(for column-width)</small></span>
     <li><span class="dfn-paneled" id="term-for-propdef-column-count" style="color:initial">column-count</span>
     <li><span class="dfn-paneled" id="term-for-propdef-column-width" style="color:initial">column-width</span>
    </ul>
   <li>
    <a data-link-type="biblio">[HTML]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-the-iframe-element" style="color:initial">iframe</span>
    </ul>
   <li>
    <a data-link-type="biblio">[mediaqueries-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-typedef-ratio" style="color:initial">&lt;ratio></span>
    </ul>
  </ul>
  <h2 class="no-num no-ref heading settled" id="references"><span class="content">References</span><a class="self-link" href="#references"></a></h2>
  <h3 class="no-num no-ref heading settled" id="normative"><span class="content">Normative References</span><a class="self-link" href="#normative"></a></h3>
  <dl>
   <dt id="biblio-css-align-3">[CSS-ALIGN-3]
   <dd>Elika Etemad; Tab Atkins Jr.. <a href="https://www.w3.org/TR/css-align-3/">CSS Box Alignment Module Level 3</a>. 6 December 2018. WD. URL: <a href="https://www.w3.org/TR/css-align-3/">https://www.w3.org/TR/css-align-3/</a>
   <dt id="biblio-css-backgrounds-3">[CSS-BACKGROUNDS-3]
   <dd>Bert Bos; Elika Etemad; Brad Kemper. <a href="https://www.w3.org/TR/css-backgrounds-3/">CSS Backgrounds and Borders Module Level 3</a>. 17 October 2017. CR. URL: <a href="https://www.w3.org/TR/css-backgrounds-3/">https://www.w3.org/TR/css-backgrounds-3/</a>
   <dt id="biblio-css-box-3">[CSS-BOX-3]
   <dd>Elika Etemad. <a href="https://www.w3.org/TR/css-box-3/">CSS Box Model Module Level 3</a>. 18 December 2018. WD. URL: <a href="https://www.w3.org/TR/css-box-3/">https://www.w3.org/TR/css-box-3/</a>
   <dt id="biblio-css-cascade-4">[CSS-CASCADE-4]
   <dd>Elika Etemad; Tab Atkins Jr.. <a href="https://www.w3.org/TR/css-cascade-4/">CSS Cascading and Inheritance Level 4</a>. 28 August 2018. CR. URL: <a href="https://www.w3.org/TR/css-cascade-4/">https://www.w3.org/TR/css-cascade-4/</a>
   <dt id="biblio-css-display-3">[CSS-DISPLAY-3]
   <dd>Tab Atkins Jr.; Elika Etemad. <a href="https://www.w3.org/TR/css-display-3/">CSS Display Module Level 3</a>. 28 August 2018. CR. URL: <a href="https://www.w3.org/TR/css-display-3/">https://www.w3.org/TR/css-display-3/</a>
   <dt id="biblio-css-images-4">[CSS-IMAGES-4]
   <dd>Tab Atkins Jr.; Elika Etemad; Lea Verou. <a href="https://www.w3.org/TR/css-images-4/">CSS Image Values and Replaced Content Module Level 4</a>. 13 April 2017. WD. URL: <a href="https://www.w3.org/TR/css-images-4/">https://www.w3.org/TR/css-images-4/</a>
   <dt id="biblio-css-logical-1">[CSS-LOGICAL-1]
   <dd>Rossen Atanassov; Elika Etemad. <a href="https://www.w3.org/TR/css-logical-1/">CSS Logical Properties and Values Level 1</a>. 27 August 2018. WD. URL: <a href="https://www.w3.org/TR/css-logical-1/">https://www.w3.org/TR/css-logical-1/</a>
   <dt id="biblio-css-overflow-3">[CSS-OVERFLOW-3]
   <dd>David Baron; Elika Etemad; Florian Rivoal. <a href="https://www.w3.org/TR/css-overflow-3/">CSS Overflow Module Level 3</a>. 31 July 2018. WD. URL: <a href="https://www.w3.org/TR/css-overflow-3/">https://www.w3.org/TR/css-overflow-3/</a>
   <dt id="biblio-css-sizing-3">[CSS-SIZING-3]
   <dd>Tab Atkins Jr.; Elika Etemad. <a href="https://www.w3.org/TR/css-sizing-3/">CSS Intrinsic &amp; Extrinsic Sizing Module Level 3</a>. 22 May 2019. WD. URL: <a href="https://www.w3.org/TR/css-sizing-3/">https://www.w3.org/TR/css-sizing-3/</a>
   <dt id="biblio-css-values-3">[CSS-VALUES-3]
   <dd>Tab Atkins Jr.; Elika Etemad. <a href="https://www.w3.org/TR/css-values-3/">CSS Values and Units Module Level 3</a>. 31 January 2019. CR. URL: <a href="https://www.w3.org/TR/css-values-3/">https://www.w3.org/TR/css-values-3/</a>
   <dt id="biblio-css-values-4">[CSS-VALUES-4]
   <dd>Tab Atkins Jr.; Elika Etemad. <a href="https://www.w3.org/TR/css-values-4/">CSS Values and Units Module Level 4</a>. 31 January 2019. WD. URL: <a href="https://www.w3.org/TR/css-values-4/">https://www.w3.org/TR/css-values-4/</a>
   <dt id="biblio-css-writing-modes-4">[CSS-WRITING-MODES-4]
   <dd>Elika Etemad; Koji Ishii. <a href="https://www.w3.org/TR/css-writing-modes-4/">CSS Writing Modes Level 4</a>. 24 May 2018. CR. URL: <a href="https://www.w3.org/TR/css-writing-modes-4/">https://www.w3.org/TR/css-writing-modes-4/</a>
   <dt id="biblio-css2">[CSS2]
   <dd>Bert Bos; et al. <a href="https://www.w3.org/TR/CSS2/">Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification</a>. 7 June 2011. REC. URL: <a href="https://www.w3.org/TR/CSS2/">https://www.w3.org/TR/CSS2/</a>
   <dt id="biblio-css3-images">[CSS3-IMAGES]
   <dd>Elika Etemad; Tab Atkins Jr.. <a href="https://www.w3.org/TR/css3-images/">CSS Image Values and Replaced Content Module Level 3</a>. 17 April 2012. CR. URL: <a href="https://www.w3.org/TR/css3-images/">https://www.w3.org/TR/css3-images/</a>
   <dt id="biblio-css3col">[CSS3COL]
   <dd>Florian Rivoal; Rachel Andrew. <a href="https://www.w3.org/TR/css-multicol-1/">CSS Multi-column Layout Module Level 1</a>. 28 May 2018. WD. URL: <a href="https://www.w3.org/TR/css-multicol-1/">https://www.w3.org/TR/css-multicol-1/</a>
   <dt id="biblio-mediaqueries-4">[MEDIAQUERIES-4]
   <dd>Florian Rivoal; Tab Atkins Jr.. <a href="https://www.w3.org/TR/mediaqueries-4/">Media Queries Level 4</a>. 5 September 2017. CR. URL: <a href="https://www.w3.org/TR/mediaqueries-4/">https://www.w3.org/TR/mediaqueries-4/</a>
   <dt id="biblio-rfc2119">[RFC2119]
   <dd>S. Bradner. <a href="https://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>. March 1997. Best Current Practice. URL: <a href="https://tools.ietf.org/html/rfc2119">https://tools.ietf.org/html/rfc2119</a>
  </dl>
  <h3 class="no-num no-ref heading settled" id="informative"><span class="content">Informative References</span><a class="self-link" href="#informative"></a></h3>
  <dl>
   <dt id="biblio-css-flexbox-1">[CSS-FLEXBOX-1]
   <dd>Tab Atkins Jr.; et al. <a href="https://www.w3.org/TR/css-flexbox-1/">CSS Flexible Box Layout Module Level 1</a>. 19 November 2018. CR. URL: <a href="https://www.w3.org/TR/css-flexbox-1/">https://www.w3.org/TR/css-flexbox-1/</a>
   <dt id="biblio-css3-break">[CSS3-BREAK]
   <dd>Rossen Atanassov; Elika Etemad. <a href="https://www.w3.org/TR/css-break-3/">CSS Fragmentation Module Level 3</a>. 4 December 2018. CR. URL: <a href="https://www.w3.org/TR/css-break-3/">https://www.w3.org/TR/css-break-3/</a>
   <dt id="biblio-html">[HTML]
   <dd>Anne van Kesteren; et al. <a href="https://html.spec.whatwg.org/multipage/">HTML Standard</a>. Living Standard. URL: <a href="https://html.spec.whatwg.org/multipage/">https://html.spec.whatwg.org/multipage/</a>
  </dl>
  <h2 class="no-num no-ref heading settled" id="property-index"><span class="content">Property Index</span><a class="self-link" href="#property-index"></a></h2>
  <div class="big-element-wrapper">
   <table class="index">
    <thead>
     <tr>
      <th scope="col">Name
      <th scope="col">Value
      <th scope="col">Initial
      <th scope="col">Applies to
      <th scope="col">Inh.
      <th scope="col">%ages
      <th scope="col">Anim­ation type
      <th scope="col">Canonical order
      <th scope="col">Com­puted value
    <tbody>
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-aspect-ratio" id="ref-for-propdef-aspect-ratio③">aspect-ratio</a>
      <td>auto | &lt;ratio>
      <td>auto
      <td>all elements except inline boxes and internal ruby or table boxes
      <td>no
      <td>n/a
      <td>discrete
      <td>per grammar
      <td>specified keyword or a pair of numbers
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-intrinsic-block-size" id="ref-for-propdef-intrinsic-block-size">intrinsic-block-size</a>
      <td>legacy | auto | &lt;length>
      <td>legacy
      <td>all elements except non-replaced inlines
      <td>no
      <td>n/a
      <td>by computed value type
      <td>per grammar
      <td>as specified, with &lt;length-percentage> values computed
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-intrinsic-height" id="ref-for-propdef-intrinsic-height②">intrinsic-height</a>
      <td>legacy | auto | &lt;length>
      <td>legacy
      <td>all elements except non-replaced inlines
      <td>no
      <td>n/a
      <td>by computed value type
      <td>per grammar
      <td>as specified, with &lt;length-percentage> values computed
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-intrinsic-inline-size" id="ref-for-propdef-intrinsic-inline-size">intrinsic-inline-size</a>
      <td>legacy | auto | &lt;length>
      <td>legacy
      <td>all elements except non-replaced inlines
      <td>no
      <td>n/a
      <td>by computed value type
      <td>per grammar
      <td>as specified, with &lt;length-percentage> values computed
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-intrinsic-size" id="ref-for-propdef-intrinsic-size①">intrinsic-size</a>
      <td>&lt;'intrinsic-width'> &lt;'intrinsic-height'>?
      <td>see individual properties
      <td>see individual properties
      <td>see individual properties
      <td>see individual properties
      <td>see individual properties
      <td>per grammar
      <td>see individual properties
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-intrinsic-width" id="ref-for-propdef-intrinsic-width②">intrinsic-width</a>
      <td>legacy | auto | &lt;length>
      <td>legacy
      <td>all elements except non-replaced inlines
      <td>no
      <td>n/a
      <td>by computed value type
      <td>per grammar
      <td>as specified, with &lt;length-percentage> values computed
   </table>
  </div>
  <h2 class="no-num no-ref heading settled" id="issues-index"><span class="content">Issues Index</span><a class="self-link" href="#issues-index"></a></h2>
  <div style="counter-reset:issue">
   <div class="issue"> This is a diff spec from <a href="https://www.w3.org/TR/css-sizing-3/">CSS Sizing Level 3</a>.
	It is currently an Exploratory Working Draft:
	if you are implementing anything, please use Level 3 as a reference.
	We will merge the Level 3 text into this draft once it reaches CR.<a href="#issue-fb4505c3"> ↵ </a></div>
   <div class="issue"> This section is a rough draft proposal.
See discussion in <a href="https://github.com/w3c/csswg-drafts/issues/333">Issue 333</a> and <a href="https://github.com/w3c/csswg-drafts/issues/1173">Issue 1173</a>.<a href="#issue-bf01a94d"> ↵ </a></div>
   <div class="issue"> Can we just slip this <a class="property" data-link-type="propdesc" href="#propdef-aspect-ratio">aspect-ratio</a> rule
		into the UA default style sheet for images,
		so that they have an aspect ratio while they load?
		This would avoid the need for extra reflows after loading.<a href="#issue-08ed422b"> ↵ </a></div>
   <div class="issue"> <strong>Need to Sync This Section With Level 3 It is Super Out Of Date</strong><a href="#issue-05e1e44b"> ↵ </a></div>
   <div class="issue"> Need to handle floats.
	See <a href="https://lists.w3.org/Archives/Public/www-style/2014Oct/0061.html">Greg’s issue</a> and <a href="https://lists.w3.org/Archives/Public/www-style/2014Nov/0085.html">dbaron’s response</a>.<a href="#issue-ac962596"> ↵ </a></div>
   <div class="issue"> ¯\_(ツ)_/¯ <a href="#issue-fbee5e7e"> ↵ </a></div>
   <div class="issue"> When we figure out how to make other physical x/y shorthands,
	like <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size">background-size</a>,
	work with logical sizes,
	we’ll apply the same logic here.<a href="#issue-7c83a0cd"> ↵ </a></div>
   <div class="issue"> Copy whatever stretch-fit ends up doing wrt margin collapsing.<a href="#issue-6e598fc0"> ↵ </a></div>
   <div class="issue"> If there is a minimum size in one dimension
	that would cause overflow of the target rectangle if the aspect ratio were honored,
	do we honor the aspect ratio or skew the image?
	If the former, we need a step similar to #2 that applies the relevant minimums.<a href="#issue-9d61aaed"> ↵ </a></div>
  </div>
  <aside class="dfn-panel" data-for="propdef-aspect-ratio">
   <b><a href="#propdef-aspect-ratio">#propdef-aspect-ratio</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-aspect-ratio">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-propdef-aspect-ratio①">(2)</a> <a href="#ref-for-propdef-aspect-ratio②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="preferred-aspect-ratio">
   <b><a href="#preferred-aspect-ratio">#preferred-aspect-ratio</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-preferred-aspect-ratio">4.1. 
Intrinsic Aspect Ratios: the aspect-ratio property</a> <a href="#ref-for-preferred-aspect-ratio①">(2)</a> <a href="#ref-for-preferred-aspect-ratio②">(3)</a> <a href="#ref-for-preferred-aspect-ratio③">(4)</a> <a href="#ref-for-preferred-aspect-ratio④">(5)</a>
    <li><a href="#ref-for-preferred-aspect-ratio⑤">4.1.1. 
Automatic Content-based Minimum Sizes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="ratio-dependent-axis">
   <b><a href="#ratio-dependent-axis">#ratio-dependent-axis</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-ratio-dependent-axis">4.1.1. 
Automatic Content-based Minimum Sizes</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="intrinsic-size">
   <b><a href="#intrinsic-size">#intrinsic-size</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-intrinsic-size">5. 
Intrinsic Size Determination</a> <a href="#ref-for-intrinsic-size①">(2)</a>
    <li><a href="#ref-for-intrinsic-size②">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="propdef-intrinsic-height">
   <b><a href="#propdef-intrinsic-height">#propdef-intrinsic-height</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-intrinsic-height">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a> <a href="#ref-for-propdef-intrinsic-height①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="propdef-intrinsic-width">
   <b><a href="#propdef-intrinsic-width">#propdef-intrinsic-width</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-intrinsic-width">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a> <a href="#ref-for-propdef-intrinsic-width①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="explicit-intrinsic-inner-size">
   <b><a href="#explicit-intrinsic-inner-size">#explicit-intrinsic-inner-size</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-explicit-intrinsic-inner-size">5. 
Intrinsic Size Determination</a> <a href="#ref-for-explicit-intrinsic-inner-size①">(2)</a> <a href="#ref-for-explicit-intrinsic-inner-size②">(3)</a>
    <li><a href="#ref-for-explicit-intrinsic-inner-size③">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a> <a href="#ref-for-explicit-intrinsic-inner-size④">(2)</a> <a href="#ref-for-explicit-intrinsic-inner-size⑤">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-intrinsic-block-size-legacy">
   <b><a href="#valdef-intrinsic-block-size-legacy">#valdef-intrinsic-block-size-legacy</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-intrinsic-block-size-legacy">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="propdef-intrinsic-size">
   <b><a href="#propdef-intrinsic-size">#propdef-intrinsic-size</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-intrinsic-size">5.6. 
Overriding Intrinsic Sizes: the intrinsic-* properties</a>
   </ul>
  </aside>
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